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A 

New  Classification  of  Human 

Tooth    Forms   With    Special 

Reference  to  a  New  System  of 

Artificial  Teeth 

J.    Leon   Williams,    D.D.S.,  L.D.S. 


Published  by 
The  DENTISTS'   SUPPLY  CO. 

220  WEST  42d  ST.,  NEW  YORK 


Reprinted  from  Dental  Digest 


Digitized  by  the  Internet  Arciiive 

in  2010  witii  funding  from 

Open  Knowledge  Commons 


http://www.archive.org/details/newclassificatioOOwill 


A   NEW   CLASSIFICATIO:^^   OF   HUMAN"    TOOTH   FOKMS; 

WITH  SPECIAL  REFEKENCE  TO  A  NEW 

SYSTEM  OF  ARTIFICIAL  TEETH. 


By  J.  Leoi^  Williams,  D.D.S.,  L.D.S. 


"It  is  only  what  happens  that  matters." 

Three  years  ago  I  presented  before  this  Society  the  outline  of  a 
scheme  for  a  system  of  artificial  teeth,  and  a  plea  for  a  new  order  of 
things  in  dental  prosthesis.  I  had  but  little  material  evidence  to  lay 
before  yon  in  support  of  the  contentions  advanced,  for  that  was  impos- 
sible. But  I  had  something  in  the  nature  of  a  vision,  in  which  I 
saw  an  important  branch  of  our  professional  service  redeemed  from  the 
low  and  almost  contemptible  position  it  has  long  remained  in.  Some- 
thing of  that  vision  I  must  have  been  able  to  get  before  you,  for  the 
substance  of  it  met  with  your  unqualified  approval  and  you  passed  a 
strongly  worded  resolution  giving  official  expression  to  that  approval 
and  asking  the  manufacturers  to  take  up  the  work  I  had  outlined  and 
proceed  with  it  along  the  lines  I  had  formulated. 

Such  an  undertaking,  at  that  time,  must  have  seemed  hazardous 
to  the  manufacturer.  It  called  for  a  very  heavy  initial  outlay.  There 
was  nothing  in  the  work  that  could  be  patented  and  no  way  in  which 
the  pioneer  in  the  new  field  could  be  protected  from  the  unfair  competi- 
tion which  imitation,  without  initial  outlay,  would  make  possible. 

But  in  spite  of  these  unfavorable  conditions  we  were  fortunate 
enough  to  find  a  manufacturing  company  with  sufficient  faith,  cour- 
age and  enterprise  to  take  up  and  carry  out  the  work  in  a  liberal 
spirit;  and  to-day  I  come  before  you  again  to  announce  the  early 
completion  of  our  long  labors. 

The  whole  scheme  which  I  laid  before  you  is  not  completed 
in  its  entirety,  but  there  is,  we  believe,  quite  sufficient  evidence  to 
offer  of  so  great  an  advance  in  this  field  as  to  make  the  old  order 
forever  intolerable,  and  thus  to  place  upon  you  the  obligation  to  so 
encourage  the  manufacturer  that  he  will  carry  all  phases  of  the  work 
through  to  its  final  consummation. 


J.  Leon  Williams,  D.D.S. 

And  now,  at  the  very  outset  of  my  lecture,  I  should  like  to  make 
it  perfectly  clear  that  this  system  of  standardizing  tooth  forms  is 
not  offered  to  the  dental  profession  as  a  mere  improvement  on  what 
has  preceded  it.  It  is  not  an  old  building  with  a  redecorated  interior 
and  a  new  facade.  It  is  a  new  structure  throughout.  Its  foundations, 
I  believe,  are  well  and  truly  laid  on  a  solid  basis  of  scientific  fact, 
with  a  superstructure  designed  in  accordance  with  a  principle  of 
unity,  without  which  good  art  is  impossible.  And  when  our  work  has 
been  carefully  examined,  when  its  full  scope  and  the  measure  of  its 
achievement  shall  have  been  clearly  seen  and  understood,  I  think 
the  universal  query  will  be  the  one  often  propounded  on  the  comple- 
tion of  some  important  undertaking  having  for  its  main  object  a 
practical  benefit  to  humanity,  "Why  was  this  not  done  before?"  The 
logic  and  reason  of  a  completed  work  is  so  frequently  self-evident  that 
we  cannot  avoid  asking  that  question.  But  in  doing  so  we  overlook 
the  tremendous  power  of  the  psychology  of  habit,  the  great  difficulty 
in  getting  outside  ourselves  for  a  point  of  view,  and  the  comforting 
feeling  of  ease  in  following  lines  of  least  resistance.  It  brings  no 
sense  of  effort  or  fatigue  to  take  a  thing  for  granted.  It  is  in  the 
overcoming  of  these  psychical  conditions  that  the  would-be  reformer 
often  finds  his  greatest  task.  And  that  is  saying  more  than  a  little  in 
this  instance,  for  the  material  conditions  have  sometimes  presented  a 
formidable  front.  But  the  knowledge  that  every  difficulty  removed 
and  every  obstacle  surmounted  has  contributed  something  toward 
placing  the  finished  work  on  a  higher  level  than  it  would  otherwise 
have  reached  is  a  very  gratifying  reflection. 

-^  «<fe  ««fe 

In  an  ancient  book  in  which  there  are  many  wise  sayings  it  is 

written:  "To  everything  there  is  a  season,  and  a  time  to  every  pur- 
pose under  the  heavens; — a  time  to  kill  and  a  time  to  heal;  a  time 
to  break  down  and  a  time  to  build  up."  To-night  I  shall  address 
myself  solely  to  the  former  of  those  two  functions.  I  have  to  under- 
take, in  the  short  space  of  an  hour  or  so,  to  break  down  the  old  sys- 
tem of  prosthetic  dentistry.^ 

From  the  standpoint  of  the  reasonableness  and  force  of  the  proofs 
at  hand,  the  task  seems  to  me  not  a  difficult  one,  but  I  should  be  a 
very  poor  student  of  human  nature  if  I  had  not  discovered  that  it 
is  far  easier  to  convince  a  man's  reason  than  it  is  to  break  up  the 
established  routine  of  his  bad  habits  in  craftsmanship  as  in  many  other 
things. 


^Only  the   first   half   of   this   paper,   the   part  devoted   to   destructive   criticism,    was    read   on 
the  date  above  mentioned.     The  latter  part  of  the  article  was  read  on  March  10. 


"A  I^Tew  Classification  of  Tooth  Foems" 

However,  I  am  greatly  encouraged  in  my  belief  that  the  bad 
old  customs  of  practice  in  dental  prosthesis  are  about  to  receive  a 
rude  shock  by  my  knowledge  of  the  fact  that  in  no  coimtry  in  the 
world  are  inferior  methods,  systems  and  machines  so  quickly  dis- 
carded or  "scrapped"  the  moment  their  inferiority  to  something  new 
is  demonstrated  and  established,  as  here  in  America.  American  busi- 
ness men  found  out  long  ago  that  it  is  the  truest  economy  and  the 
surest  way  to  success  to  throw  away  an  inferior  method  of  produc- 
tion, or  a  method  which  produces  an  inferior  article,  the  instant  better 
methods  are  discovered.  That  policy  has  made  Americans  the  great- 
est leaders  in  the  business  world.  It  has  sent  all  the  nations  of  the 
earth  here  to  learn  and  copy  American  methods,  and  to-day  you  may 
find  those  methods  being  put  into  effect  in  the  remotest  corners  of 
the  world.  So  strong  and  vital  is  this  influence  of  American  progress 
that  Gugiielmo  Ferrero,  the  distinguished  Italian  historian,  says  "it 
is  the  one  idea  that  has  taken  deep  hold  of  the  European  masses 
during  the  last  fifty  years."  It  has  certainly  created  a  new  outlook 
and  a  new  spirit  in  the  world.  It  has  made  men  more  self-reliant 
and  given  them  a  greater  confidence  in  their  own  inherent  capacity 
to  subdue  the  stubborn  and  apparently  antagonistic  forces  of  ISTature 
to  human  will.  It  is  in  that  American  spirit  which  says,  in  the 
language  of  the  people,  "The  best  we  can  have  is  none  too  good,"  that 
I  have  come  here  to-day  to  ask  you  to  discard,  to  throw  away,  to  utter- 
ly destroy  and  obliterate  a  system  of  prosthetic  dentistry  that  has  ex- 
isted far  too  long,  and  to  establish  in  its  place  something  more  in 
keeping  with  the  reputation  for  progress  and  scientific  achievement 
and  character  that  our  country  enjoys  in  other  fields  throughout  the 
world. 

•^  *%  '^ 

Dr.  Ebersole,  in  a  stirring  and  eloquent  call,  published  in  the 
Dental  Summary  last  January,  warned  you  that  dentistry  was  not 
keeping  in  the  van  of  American  progress.  If  that  is  true  in  any 
degree  of  dental  practice  as  a  whole,  then  it  is  most  emphatically  true 
of  dental  prosthesis.  And  on  that  point  I  believe  there  are  no  two 
opinions. 

To  remedy  the  present  deplorable  condition  of  things  in  this 
field  the  first  important  step  is  to  find  out  the  cause  or  causes  of  this 
condition.  In  my  judgment,  the  chief  cause  is  to  be  found  in  the 
false  basis  of  the  present  methods  and  theories  for  the  selection  of 
porcelain  teeth  and  it  is,  as  I  have  indicated,  principally  with  this 
theme  that  I  shall  deal  this  evening. 


J.  Leon  Williams,  D.D.S. 

I  believe  that  the  chief  reason  why  prosthetic  dentistry  has  fallen 
so  low  in  the  estimation  of  the  profession  is  that  most  dentists  have 
an  instinctive  feeling  that  with  such  teeth  as  have  heretofore  been 
supplied,  no  amount  of  effort  on  their  part  would  produce  satisfactory 
scientific  and  artistic  results.  I  wish,  therefore,  to  try  and  make  it 
clear  why  the  present  system  is  weak  and  poor.  I  want  to  point 
out  its  imperfections  and  fallacies,  its  dogmatic  assumptions  that 
have  no  foundations,  its  ignorance  of  scientific  facts  and  artistic  prin- 
ciples, so  that  there  may  be  no  qualms  of  conscience,  no  shadow  of 
regret  in  saying  good-bye  to  it.  This  will  take  a  little  more  of  your 
time  than  you  are  accustomed  to  give  to  listening  to  a  paper  or  lecture. 
But  I  ask  you  to  remember  that  the  occasion  is  a  little  unusual. 
You  are  not  often  asked  to  listen  to  reasons  why  you  should  make  a 
complete  and  radical  change  in  an  important  branch  of  practice. 

Two  great  defects  have  characterized  the  manufacture  of  arti- 
ficial teeth  from  the  date  of  their  invention  do\vn  to  the  present  time, 
a  conventionalized  or  generalized  tooth  form,  devoid  of  definite  char- 
acter, and  the  absence  of  any  system  of  classification,  or  any  funda- 
mental principle  or  central  idea  on  which  the  work  is  based.  This 
statement  applies  with  equal  force  to  the  shapes  of  the  incisors  and 
the  masticating  surfaces  of  the  bicuspids  and  molars. 

'^  '^  '^ 

There  are  very  definite  reasons  why  artificial  teeth  should  have 
continued  to  remain,  for  such  a  long  period  in  the  history  of  dentistry, 
of  a  defective  and  unnatiural  character  and  without  systematic  ar- 
rangement. It  was  hardly  possible  to  have  any  satisfactory  classifica- 
tion of  natural  teeth,  neither  was  it  possible  to  have  fine,  natural, 
artistic  forms  of  artificial  teeth  without  a  knowledge  of  the  primary 
forms  of  natural  teeth.  That  statement  may  sound  somewhat  curi- 
ous to  you,  but  I  hope  to  make  it  quite  clear,  presently,  that  the  pri- 
mary forms  of  human  teeth  have,  hitherto,  not  been  known.  Like 
old  friends,  whom  we  sometimes  meet  and  pass  on  the  streets  when 
our  minds  are  preoccupied,  they  have  been  seen  and  not  recognized.^ 

But  to  produce  a  perfect  system  of  artificial  teeth  there  is  re- 
quired not  only  an  intimate  knowledge  of  all  the  facts  of  ISTature,  but 
also  familiarity  with  the  principles  of  design  through  which  a  har- 
mony of  related  parts,  that  is  often  absent  in  ISTature,  may  be  secured. 


SMany   examples   could   be    adduced   to   show   that   long   observation   does   not   always    result 
in   accurate   perception.      Herbert    Spencer,   at   different   periods   in   his   life,    held    three   distinct 
opinions   about    the   color   of   shadows,    each    one,    as    he    says,    "based    on   years    of    observation. 
And  his  final  recognition   of  what   he   regarded  as   the  exact  truth   was  due  to   a  suggestion   he 
got   while   reading   a   popular   work  on   optics. 


"A  !N'ew  Classificatioit  of  Tooth  Fokms" 

This  very  essential  qualification  for  tlie  production  of  artificial  teeth 
seems  to  have  been  entirely  overlooked. 

As  a  matter  of  fact,  no  serious  attempt  has  ever  before  been 
made  to  investigate  any  portion  of  this  field  with  scientific  thorough- 
ness and  accuracy.  All  the  honors  in  dentistry  have  been  reserved 
for  other  departments,  with  the  result  that  many  men  who  have  na- 
tional reputations  in  what  is  called  operative  dentistry,  make  a  mighty 
poor  showing  when  they  turn  their  hands  to  dental  prosthesis. 

Whether  or  not  the  reason  for  this  is  the  one  I  have  suggested,  it 
is,  nevertheless,  certain  that  this  branch  of  practice  presents  a  far 
finer  opportunity  for  the  exercise  of  artistic  skill,  scientific  knowledge 
and  sound  judgment  than  is  to  be  found  in  any  other  phase  of  den- 
tistry. If  any  one  has  any  doubts  on  that  point  I  hope  he  will  reserve 
his  final  opinion  until  he  has  heard  the  full  "argument  for  the  plain- 
tiff." 

<^  «^  -^ 

You  will,  I  think,  be  able  to  see  more  clearly  the  relation  and 
significance  of  the  facts  presented  if  I  state  specifically  the  main 
objects  I  have  in  view  in  this  paper.  I  shall  attempt  to  destroy  all 
belief  in  temperamental  forms  of  teeth,  for  I  regard  this  as  one  of 
the  most  fundamental  errors  in  the  present  system.  I  shall  try  to 
show  that  while  there  are  slight  variations  in  the  teeth  of  different 
peoples,  there  is  no  such  thing  as  racial  types  of  teeth.  I  hope  to 
convince  you  that  the  oft  repeated  statement  that  Nature  always  pro- 
duces teeth  in  harmony  with  face  and  feature  is  a  mistake  due  to 
lack  of  careful  observation.  And  I  expect  to  prove  that  it  is  impos- 
sible to  produce  a  scientific  and  satisfactory  system  of  artificial  teeth 
by  simply  copying  sets  of  natural  teeth. 

Let  us  begin  then,  with  the  subject  of  temperamental  classifica- 
tion of  teeth.  And  let  me  note  at  the  outset  that  some  of  our  best 
writers  on  dental  prosthesis  say  quite  frankly  that  they  make  use  of 
this  theory  for  lack  of  a  better. 

In  his  excellent  book,  recently  published,  my  good  friend.  Dr. 
Wilson,  of  Cleveland,  has  introduced  a  brief  resume  of  the  theory, 
but  I  think  I  discover  evidences  that  he  is  not  altogether  satisfied  with 
it.  Other  writers,  after  admitting  that  there  are  great  variations 
within  the  limits  of  the  normal,  afterwards  say  that  with  few  excep- 
tions the  forms  and  contours  of  the  teeth  are  harmonious  with  those 
of  the  body,  but  they  give  us  neither  principles  nor  facts  on  which 
such  a  statement  is  founded. 


J.  Leon  Williams,  D.D.S. 

One  author  savs  further  that  "it  is  difficult,  in  some  cases,  to  de- 
cide positively  to  which  variety  (of  temperament)  a  special  case  be- 
longs .  .  .  K^ot  infrequently  the  indications  are  even  contradic- 
tory .  .  .  and  no  rule  can  he  given  that  will  not  fail  in  numerous 
instances."  I  submit  that  a  theory  of  this  character  is  much  more 
likely  to  mislead  than  guide  the  student  and  beginner,  and  that  it 
would  have  been  better  to  drop  it  altogether  in  dentistry,  as  was  done 
in  other  branches  of  science  long  ago.  But  this  course  has  not  been 
taken,  and  the  theory  still  has  some  ardent  and  dogmatic  advocates. 
I  am  sure  you  will  agree,  therefore,  that  it  is  better  to  subject  the 
claims  of  this  teaching  to  a  thorough  critical  examination  before  put- 
ting forward  the  new  classification. 

'fe  -^  «^ 

Let  us  first  glance  at  the  great,  authoritative  modern  works  of 
reference,  to  see  what  they  have  to  say  on  the  subject  of  temperament. 

Our  first  effort  is  a  little  disappointing. 

We  open  the  Encyclopaedia  Britannica  at  the  place  where  the 
word  should  be,  but  we  do  not  find  it.  It  is  completely  ignored.  We 
consult  the  Xew  American  Encyclopaedia  of  Science  and  do  not  fare 
much  better.  The  word  is  there,  it  is  true,  but  used  in  a  sense  that 
connotes  nothing  of  the  physical  or  mental  characteristics  of  human 
beings.  It  simply  has  reference  to  certain  technical  matters  about 
musical  instruments.  Gould's  Dictionary  of  Medicine  says  that  the 
word  is  spoken  of  as  a  vague  term  or  a  term  vaguely  applied.  This 
authority  further  says  that  although  the  original  doctrine  has  long 
since  lost  its  sigTiificance,  it  is  permissible  to  use  it  in  describing  pre- 
disposition to  types  of  mental  action :  and  that  is  the  manner  in  which 
it  is  sometimes  used  by  good  modern  writers.*  Jonathan  Hutchinson, 
F.R.S.,  with  whose  work  on  the  teeth  you  are  all  familiar,  made  a 
careful  examination  of  the  claims  of  the  temperamentalists  and  here 
is  his  verdict:  "As  yet  I  fear  we  must  say  that  the  labors  of  the 
physiognomist  and  those  of  the  students  of  temperament  have  been 
alike  disappointing.  Whoever  will  set  himself  the  task  of  attempt- 
ing to  classify  a  given  number  of  individuals  according  to  their  tem- 
peraments will,  I  think,  soon  find  himself  baffied." 

The  simple  truth  of  the  matter  is  that  this  whole  theory  of  tem- 
perament has  been  completely  discredited  and  entirely  abandoned  by 


*Dr.  E.  B.  Taylor,  F.R.S.,  author  of  an  important  work  on  Anthropology,  says:  "Anthro- 
pology finds  race-dififerences  most  clearly  in  stature  and  proportions  of  limbs,  conformation  of 
the  skull  and  the  brain  within,  characteristics  of  features,  skin,  eyes  and  hair,  peculiarities  of 
constitution,  and  mental  and  moral  temperament."  The  italics  are  mine.  Dr.  Keane,  one  of 
the  very  greatest  authorities  in  Anthropology,  applies  the  word  "temperament"  solely  to  psy- 
chical  qualities. 

6 


'"A  'Nnw  CiiAssiFiCATioisr  or  Tooth  Foems" 

all  scientific  men  of  standing — except  a  few  of  those  who  rule  over 
the  destinies  of  dentistry.  And  for  them  I  fear  that  a  mere  reference 
to  authorities,  however  eminent,  will  hardly  be  sufficient.  We  shall 
have  to  go  a  little  deeper  into  the  matter,  to  completely  satisfy  them. 
But  before  getting  down  to  the  real  work  of  proof,  let  us  have  a  side- 
long glance  at  those  pretentious  tables  of  temperamental  classifications 
with  their  air  of  exhaustive  research  and  minute  discrimination,  which 
figure  so  prominently  in  our  textbooks  on  prosthetic  dentistry. 

You  are  all  familiar  with  the  results  of  the  researches  of  Dr. 
Black  and  Mr.  Charles  Tomes  into  the  question  of  comparative  hard- 
ness or  softness  of  teeth.  You  know  that  working  quite  independ- 
ently they  both  reached  the  conclusion  that  the  variation  in  the  hardness 
and  softness  of  teeth  was  a  negligible  quantity.  The  differences  are 
so  small  as  to  be  a  matter  of  no  importance.  But  if  we  turn  to  those 
tables  in  our  textbooks  on  prosthetic  dentistry  which  profess  to  give  the 
temperamental  characteristics  of  teeth,  we  find  the  so-called  lymphatic 
teeth,  and  combinations  of  the  lymphatic,  bilious  and  nervous  teeth, 
described  as  "soft  and  brittle" ;  ''soft  and  frail" ;  "soft  and  weak" ; 
"soft  and  sensitive" ;  "mixture  of  flinty  and  chalky" ;  "soft,  weak  and 
chalky,"  etc.,  etc. 

'^  '^  '^ 

I  shall  show  you  presently  that  all  so-called  temperamental  char- 
acteristics must  have  arisen  in  racial  characteristics.  With  that  fact 
in  view,  the  question,  "Do  those  races  from  which  the  so-called  lym- 
phatic, bilious  and  nervous  temperaments  have  arisen  have  teeth  that 
are  markedly  more  soft  and  frail  than  the  sanguine  races  ?"  need  only 
be  asked  to  see  the  utter  absurdity  of  the  whole  business  stand  revealed, 
even  without  the  classical  work  of  Black  and  Tomes  to  prove  it. 

Then  take  the  indications  as  to  shape  and  size.  We  are  told  that 
the  teeth  of  a  bilo-nervous  person  are  "medium  large"  and  "long  and 
often  narrow"  in  shape,  while  the  nervo-bilious  teeth  may  be  "large 
or  small"  and  "broad  or  long."  Is  that  the  sort  of  instruction  a  dental 
student  requires  to  enable  him  to  produce  harmonious  relations  be- 
tween tooth  form  and  facial  contour  ?  If  you  were  given  a  blank  form 
of  face  of  a  definite  size  and  of  the  oval  type,  let  us  say,  and  required 
to  describe  the  character  of  the  features  necessary  to  produce  an  har- 
monious whole,  would  you  say  that  the  mouth  might  be  short  or  long, 
the  nose  large  or  small,  the  eyes  near  or  widely  separated  ?  In  all  the 
wearisome  contradictory  and  irrelevant  details  of  these  tables  there  is 
never  a  hint  of  fundamental  principle  on  v/hich  a  student  could  take 
his  stand  for  the  exercise  of  his  taste  and  judgment, 

7 


J.  Leox  Williams,  D.D.S. 

Many  of  vou  will  remember  that  in  the  paper  which  I  read  here 
three  years  ago  I  pointed  out  that  there  was  really  no  foundation  for 
the  theory  of  tempersimental  forms  of  teeth.  I  exliibited  photographs 
of  individuals  of  precisely  the  same  temperaments,  according  to  the 
rules  of  the  theory,  but  showing  teeth  widely  different  in  shape.  Since 
then  text  books  on  prosthetic  dentistry  have  appeared  in  which  this 
theory  is  given  a  prominent  place.  But  even  more  significant,  per- 
haps, is  the  prominence  given  to  this  theory  in  the  recently  issued 
catalogues  of  two  of  the  oldest  and  most  prominent  manufacturers  of 
artificial  teeth.  I  say  ''more  significant"  because  the  prominent  manu- 
facturers have  the  best  of  reasons  for  making  it  their  business  to  know 
the  general  trend  of  belief  and  opinion  in  the  profession. 

In  the  latest  catalogue  of  one  of  the  largest  and  oldest  firms  in 
England  we  find  illustrations  of  the  three  sets  of  teeth  in  the  lower 
row  of  Illustration  Xo.  1,  and  at  the  bottom  of  the  pages  on  which 
they  are  sho^vn  we  read — "The  dentures  illustrated  above  are  distinct- 
ly typical  of  the  temperaments  described  by  Spurzheim,"  and  then, 
as  though  to  specially  emphasize  the  statement  that  these  particular 
teeth  are  '^'^ distinctly  typical/'  they  add  that  ''it  must  be  remembered 
that  a  pure  type  is  seldom  met  with,  the  majority  of  the  cases  being 
combinations  of  the  features  of  more  than  one  temperament."  The 
temperaments  represented  in  the  three  dentures  I  have  selected  are 
supposed  to  be  the  "sanguine,"  the  "bilious"  and  the  "nervous."  I 
will  ask  you  to  look  very  closely  at  the  central  incisors,  always  the 
most  characteristic  teeth  in  any  given  set.  and  see  if  you  can  detect 
the  very  least  typical  difference.  The  teeth  are  not  only  of  one  type, 
but  they  are  very  nearly  indistinguishable  as  to  form  and  size.  Except 
as  to  color,  there  is  not  a  ghost  of  a  reason  why  these  sets  should  not 
all  change  places. 

'^  '^  '^ 

A  representative  American  firm  has  also  published  illustrations 
of  teeth  designed  for  the  pure  temperaments,  as  shown  in  the  upper 
row  of  illustration  ^o.  1. 

Please  compare  the  corresponding  t%^es  of  the  two  manufactur- 
ers. Xo  comment  from  me  is  necessary,  and  I  will  make  none,  except 
to  say  that  these  teeth  are  not  made  by  firms  whose  reputation  is  ever 
called  in  question.  They  are  firms  which  are  rightly  and  justly  jeal- 
ous of  the  high  reputation  they  have  honorably  earned.  But  can  you 
look  at  the  specimens  of  these  two  companies,  each  claiming  its  own 
work  as  typical,  and  each  so  widely  dift'erent  from  the  other  as  to 
make  comparison  positively  grotesque,  without  thinlving  that  it  is  about 
time  we  heard  the  last  of  temperamental  classification  of  teeth;    that 

8 


SANOUISI-IOUS 


CM?  fBSflP   f!RW 


Illustration  No.   1 

Lower  row,  three  sets  of  teeth  from  a  well-known  English  manufacturer  supposed  to  be 
typical  of  the  temperaments  described  by  Spinzheim.  All  three  sets  are  of  one  type,  but  very 
nearly  of  one  form  of  that  type. 

The  upper  row  shows  three  sets  made  for  these  same  temperaments  by  a  long-established 
American  manufacturer.  Each  form  is  so  different  from  the  form  of  the  English  manufacturer 
for  the   same   temperament   as   to   make   comparison   diificult. 


Illustration  No.  2 

Two  skulls  of  unlike  form  with  teeth  identical   in  type  and  size.     No   relation  between   form 
or  size  of  skull  and  the  form  or  size  of  teeth. 


"A  IsTew  Classification  of  Tooth  Eoems" 

it  is  about  time  we  began  looking  for  something  a  little  more  scientific 
as  a  basis  for  tooth  form,  and  also,  if  I  may  say  so,  about  time  that 
some  one  designated  and  officially  indorsed  by  the  profession,  to  ex- 
press their  views  and  wishes,  took  a  hand  in  the  designing  of  artificial 
teeth? 

There  are  several  phases  of  this  theory  of  temperament,  but  they 
all  overlap  more  or  less.  This  may  sometimes  cause  an  unavoidable 
appearance  of  redundance  in  the  proofs  brought  against  these  different 
phases.  And  I  fear  that  this  fault  of  redundance,  or  perhaps  it  might 
more  correctly  be  called  repetition,  will  appear  more  or  less  through- 
out the  paper.  There  is  so  much  that  is  entirely  new  and  foreign  to 
all  former  teaching  in  my  paper,  that  it  has  seemed  to  me  often  neces- 
sary to  present  the  same  facts  from  more  than  one  point  of  view. 

One  writer  on  the  subject  of  temperament  says:  "In  these  tem- 
peramental differences,  no  single  sig-n  is  more  sig-nificant  than  is  to 
be  found  in  the  physical  characteristics  of  the  teeth — their  size,  shape, 
color,  density  and  alignment  being  as  much  an  index  as  is  the  distinc- 
tive complexion,  the  color  of  the  eyes,  hair,  etc."  A  little  farther 
down  the  page  it  is  said:  "The  law  of  harmony  thus  found  in  ISTature 
between  the  teeth  and  other  physical  characteristics  requires — "  etc., 
etc.  And  once  more:  "The  careful  observation  and  recording  of  these 
co-relations  would  go  far  toward  making  prosthetic  dentistry  an  exact 
science."  Here  we  have  three  variations  of  an  assumption  that  iSTature 
always  produces  teeth  that  in  form  and  size  are  in  perfect  harmony 
with  the  face  and  the  individual  features  of  the  face.  We  often  meet 
this  assumption  in  our  text  books  and  in  magazine  articles.  On  what 
is  it  founded  ? 

•^  '^  '% 

I  have  never  heard  anyone  assert  that  all  the  other  features  of 
every  human  face  were  in  perfect  harmony.  The  most  of  us  have 
seen  many  faces  on  which  we  would  pass  the  observation  of  old  Omar 
Khayyam — if  the  "sorry  scheme  of  things"  were  entrusted  to  us  "would 
we  not  shatter  it  to  bits  and  then  remould  it  nearer  to  our  heart's 
desire  ?"  The  great  teacher  of  science,  Haeckel,  is  almost  brutal  in 
his  remarks  on  this  point.  He  says  in  his  "Evolution  of  Man" :  "If 
we  compare  the  face  of  the  long-nosed  ape  with  that  of  abnormally  ape- 
like human  beings,  the  former  will  be  admitted  to  represent  a  higher 
stage  of  development.  There  are  still  people  among  us  who  look  especially 
to  the  face  for  the  'image  of  God  in  man.'  The  long-nosed  ape  would 
have  more  claim  to  this  than  some  human  individuals  one  meets."  Is 
there  anything  more  evident  to  us  as  we  walk  up  and  down  the  streets 
or  stand  in  any  place  where  our  fellow  mortals  congregate,  than  the 

9 


J.  Leon  Williams,  D.D.S. 

incongruities  of  Nature?  Even  the  most  fortunate  would  probably 
not  be  willing  to  give  an  absolutely  unqualified  receipt  in  full  to  Na- 
ture on  taking  a  critical  survey  of  himself  in  his  mirror.  Why,  then, 
should  we  assume  that  Nature  always  produces  teeth  in  perfect  har- 
mony with  face  and  features?  Why  should  they  be  an  exception  to 
the  almost  universal  rule  to  the  contrary  in  other  particulars  'i  The  only 
explanation  I  can  suggest  for  this  strange  inconsistency  is  that  an  accept- 
ance of  the  temperamental  theory  made  it  necessary.  It  is,  in  fact,  a 
phase  of  that  theory.  And  when  we  have  once  given  our  unreserved 
consent  to  a  theory  it  is  astounding  how  completely  oblivious  we 
become  to  the  most  obvious  facts.  Let  me  put  a  few  of  the  facts  bear- 
ing on  this  question  before  you.  Here  is  a  photograph  of  two  skulls 
(Illustration  No.  2).  You  will  observe  that  the  difference  in  general 
contour  is  very  marked.  But  the  teeth,  you  see,  are  identical  in  size  and 
type.  If  either  set  is  in  perfect  harmony  with  size  and  contour  of  face, 
the  other  set  cannot  possibly  be  so. 

Here  are  two  more  (Illustration  No.  3),  a  very  wide  and  a  very 
narrow  skull.  Think  what  a  striking  difference  there  must  have  been 
in  the  facial  contour  of  the  two  individuals  those  skulls  represent.  But 
you  see  the  widest  and  shortest  teeth  are  in  the  long,  narrow  skull.  And 
here  (Illustration  No.  4)  are  two  more  from  the  Andaman  Islands — 
both  skulls  from  the  same  race.  Here  again  the  smaller  skull  has  the 
larger  teeth.    Note  also  that  they  are  not  of  a  different  type. 

'^  '^  '^ 

Here  we  have  four  skulls  (Illustration  No.  5)  so  nearly  alike  in 
size  and  contour  that  a  single  set  of  teeth  would  be  just  as  suitable  for 
one  as  another  of  them,  but  look  at  the  difference  in  the  natural  teeth. 
At  least  three  of  those  must  be  examples  of  disharmony.  A  glance  at 
the  teeth  is  sufficient  to  demonstrate  the  mistakes  of  Nature.  I  could 
take  up  the  whole  evening  in  showing  you  examples  of  this  sort, 
but  as  further  proof  on  this  point  will  appear  incidentally  when  I 
am  considering  other  phases  of  my  subject,  I  will  not  dwell  longer 
on  it  now.  Unless  someone  can  advance  good  and  satisfactory  reasons 
for  believing  that  Nature  is  more  solicitous  about  the  harmonious 
relations  of  our  dental  organs  with  other  features  than  she  is  about 
those  of  our  eyes,  ears  or  noses,  we  will  conclude  that  the  subject  is  al- 
ways open  to  the  intelligent  criticism  of  an  artist  in  teeth. 

The  advocates  of  the  temperamental  theory  always  assume  that 
when  a  man  and  a  woman  of  opposite  temperaments  mate,  the  off- 
spring will  be  a  blend  of  the  two  temperaments.  To  a  certain  limited 
extent  this  may  sometimes  be  the  case,  but  more  frequently  we  see  a 
juxtaposition,  so  to  say,  of  the  salient  features  of  both  parents.     This 

10 


Illustration   No.    3.     The   widest   and  shortest  teeth   are   in   the   narrow   skull 


Illustration  No.  4.     Two  skulls  from  the  Andaman  Islands.     The  smaller  skull  has  the  larger  teeth 
and    of    different    type,    than    the    other 


"A  N^EW   CLASSIFICATIOISr  OF   ToOTH  FoKMs" 

might  ]iave  been  known  either  from  observation  or  from  a  knowledge 
of  the  more  recent  researches  in  heredity. 

The  works  of  Mendel,  Weissman,  Galton,  Thomson,  Bateson  and 
others  have  made  it  clear  that  certain  characters  are  dominant  in  one 
parent  and  other  characters  in  the  other.  One  child  may  inherit  the 
general  facial  peculiarities  of  the  father,  and  the  complexion,  color 
of  eyes  and  hair,  and  the  teeth  of  the  mother.  In  another  child  these 
conditions  may  be  reversed.  In  Sicily,  that  old  battle  ground  of  the 
races,  where  the  blood  of  the  blue-eyed,  fair-haired  followers  of  JSTor- 
man  Roger  has  mingled  with  that  of  the  Arabs,  I  ha,ve  often  seen  just 
such  effects  of  this  crossing  of  types  as  I  have  mentioned,  and  one  may 
see  in  Ireland  people  with  black  hair,  dark  skin  and  blue  eyes.^ 

What  is  the  value  of  the  temperamental  theory  of  tooth  form  in 
instances  like  these? 

Wfe  <<fe  <^ 

And  now,  consider  for  a  moment  the  basis  on  which  the  whole 
theory  rests.  It  is  founded  on  the  idea  of  four  groups  or  classes  of 
individuals  called  the  pure  temperamental  types  and  known  as  the 
sanguine,  the  nervous,  the  bilious  and  the  lymphatic,  in  accordance 
with  the  alleged  dominance  of  the  physiological  functioning  of  the 
blood,  the  nerves,  the  bile,  or  the  lymph.  What  do  the  advocates  of 
this  theory  mean  by  the  dominance  of  these  systems  ?  Obviously  but 
one  thing  can  be  meant,  and  that  is  that  the  action  of  the  heart  or 
the  liver  or  the  lymphatic  system  or  the  nervous  system  is  stronger  or 
dominant  in  the  individuals  characterized  by  these  terms.  People  of 
the  sanguine  temperament  should  show  a  stronger  action  of  the  heart, 
those  of  the  bilious  temperament  greater  activity  of  the  liver  and 
people  of  the  nervous  temperament  should  be  distinguished  by  greater 
intellectual  achievements  and  brain  power  generally. 

Well,  I  have  a  large  collection  of  photographs  of  some  of  the  most 
eminent  persons  of  this  country  and  Europe  and  I  find  that  all  forms 
of  faces  and  physical  characteristics  are  included  among  the  ablest 
and  most  intellectual  people  of  the  world. 


^Broca  and  Thurnam,  in  the  Memoirs  of  the  Anthropological  Society,  describe  a  group  of 
sixteen  ancient  skulls,  nearly  all  perfect,  found  in  France  at  Nogent-les-Vierges.  Three  of 
them  are  described  as  the  dolichocephalic  skulls  of  Aryan  stock,  eight  as  the  brachycephalic 
of  Mongolian  origin  and  five  as  a  cross  of  the  two.  These  latter  had  the  high,  narrow  fore- 
head of  the  long  headed  race,  while  the  middle  and  occipital  regions  of  the  skulls  had  the 
width   and   fulness    of   the   round   headed    race. 

Thomson,  in  his  fine  work,  "Heredity,"  says:  "A  white  man  of  considerable  intellectual 
ability  marries  a  negro  woman  of  great  physical  beauty  and  strength:  the  result  may  be — has 
been  a  mulatto,  who  inherits  some  of  his  father's  intellectual  virtue  and  some  of  his  mother's 
physical  strength."  Again,  "If  a  tall  variety  of  (sweet)  pea  be  crossed  with  a  dwarf,  all  the 
offspring  are  tall,  and  among  their  offspring  in  turn  three-fourths  are  tall  and  one-fourth 
dwarf,    but   none   between    the    two."      The   italics    are   mine. 

Thomson  further  says,  when  speaking  of  Mendel's  law:  "Experimental  work  has  driven 
home   the   conception    of   unit   characters     .     .     .     that   are    inherited   independently. 

11 


J.  Leon  Williams,  D.D.S. 

But  it  may  be  pertinent  to  ask  who  lias  ever  made  any  experi- 
ments of  a  severely  scientific  character  to  prove  that  the  action  of  the 
heart  is  stronger  in  so-called  sanguine  persons,  or  the  liver  more  active 
in  bilious  persons,  or  the  brain  larger  in  the  alleged  nervous  tempera- 
ment ?  Who  has  ever  conducted  such  experiments  to  prove  anything 
about  temperament  as  indicative  of  physical  characteristics  ? 

Who  has  ever  determined  the  temperament  of  a  negro  or  an  Arab  ? 
Are  the  individuals  of  all  races  except  Europeans,  alike  in  their  phys- 
ical and  psychical  characters  ?  If  not,  what  physical  peculiarities  in  a 
Chinaman,  a  native  of  iiustralia  or  a  Hindoo  correspond  to  those  al- 
leged to  be  indicative  of  the  nervo-sanguine  temperament  in  an  Ameri- 
can? 

Who  has  ever  got  together,  even  a  dozen  people  of  one  tempera- 
ment, selecting  them  by  their  alleged  physical  temperamental  peculiar- 
ities witliout  looking  at  their  teeth,  and  then  examined  the  teeth  to 
see  if  they  were  all  alike  or  of  one  type  ? 

If  that  simple  experiment  had  ever  been  made  it  would  have 
been  seen  that  this  pretentious  structure  (the  temperamental  theory) 
is  as  frail  as  a  house  of  cards  and  as  empty  as  a  soap  bubble.  A  recent 
writer  in  the  Edinburgh  Review  says:  ''The  greatest  discovery  ever 
made  in  philosophy  was  that  the  way  to  discover  whether  a  thing  is 
present  is  to  look  and  see.  It  was  proclaimed  by  Aristotle  in  the  an- 
cient world  and  by  Francis  Bacon  in  the  modern  world."  The  extent 
to  which  that  simple  rule  is  neglected  is  one  of  the  astounding  things 
of  life.  ^  ^  ^ 

And  now  let  me  lay  before  you  the  final  and  crushing  proofs  of 
the  utter  futility  and  fallacy  of  this  theory. 

What  is  the  origin  of  those  physical  characteristics  that  are  called 
temperamental?  You  have  on  the  screen  pictures  from  life  in  which 
are  represented  the  three  great  races  from  which  it  is  believed  all  the 
modern  peoples  of  the  earth  have  arisen.  The  black  race  is  represent- 
ed by  the  South  African  Medicine  Man;  the  yellow  Mongolian  race 
by  the  group  of  Chinese;  and  the  Caucasian  peoples  by  the  blue-eyed 
ISTorwegian  bride.  The  three  distinct  types  of  skulls,  long,  broad  and 
medium,  most  characteristic  of  distinct  races,  are  also  represented  in 
these  three  types. 

Away  back  in  neolithic,  or  even  in  paleolithic  times,  there  were 
two  races  in  Europe — the  long-headed  or  dolichocephalic  type,  and 
the  broad  or  round  heads,  the  brachycephalic  type.*' 


''Professor  Duckworth,  of  Cambridge,  England,  writing  of  the  Krapina  skull,  says:  "It  is 
shown  that  early  paleolithic  man  presents  examples  of  skulls  both  of  brachy-cephalic  and 
dolicho-cephalic  proportions." 

12 


"A  ^EW  Classification  of  Tooth  Foems" 

The  Caucasian  race  is,  possibly,  a  later  evolutionarj  development. 

The  portraits  I  have  just  shown  may  be  taken  as  the  modern 
representatives  of  those  ancient  races.  Broadly  speaking,  the  fair 
races,  and,  to  a  large  extent,  the  yellow  races,  are  found  in  ISTorthern 
and  Central  Europe  and  Asia,  while  the  darker  races  occupy  the 
Equatorial  and  southern  regions.  From  the  mingling  of  those  light 
and  dark  races,  the  working  of  the  principle  of  variation,  and  the  modi- 
fying effects  of  climate  and  general  environment,  there  has  arisen  all 
the  racial  or  temperamental  characters  that  the  widely  varied  inhabi- 
tants of  the  earth  exhibit. 

There  are  many  theories  and  there  is  much  speculation  about  these 
ancient  races,  but  all  theories  and  all  known  facts  are  in  agreement 
on  the  point  of  the  meeting  and  mixing  of  dolichocephalic  and  brachy- 
cephalic  races  in  Europe  in  prehistoric  times. 

It  is  a  very  fascinating  theme,  but  we  cannot  dwell  upon  it  now, 
and  the  main  facts  are  all  that  is  necessary  to  our  purpose  in  tracing 
the  origin  of  temperament.  What  we  really  know  beyond  controversy 
is  that  everything  denoted  by  the  term  temperament  must  have  arisen 
in  or  originated  from  race.  We  can  see  clearly  enough  that  most  of 
the  peculiarities  described  as  sanguine  must  have  been  transmitted  by 
the  Caucasian  race,  while  the  bilious  features  were  inherited  from  the 
dark  races,  and  the  Mongols  have  most  of  the  distinctive  traits  called 
"lymphatic." 

'^  '^  '^ 

If  we  now  open  a  book  such  as  Stewart's  on  "Our  Temperaments," 
the  latest  and  best  work  on  the  subject  that  I  have  seen,  and  find 
portraits  of  such  individuals  as  those  now  shown  on  the  screen,  we 
know  that  the  physical  or  so-called  temperamental  characters  which 
they  present  did  not  arise  spontaneously  and  without  cause.  The  im- 
mediate ancestors  of  that  man  with  red  hair  and  blue  eyes  were  not 
natives  of  Africa.  The  parents  of  that  swarthy  individual  with  dark 
complexion  and  black  eyes  and  hair  were  not  full  blooded  Swedes  or 
I^orwegians;  and  we  can  predict  with  reasonable  certainty  that  there 
is  a  Mongolian  strain  in  that  so-called  lymphatic  person  with  the 
pipe  who  looks  so  comfortable  and  altogether  satisfied  with  himself. 
In  other  words,  we  can  discover  no  special  trait  or  characteristic  in 
these  individuals  who  are  supposed  to  be  representative  of  the  differ- 
ent temperaments,  that  is  not  even  more  clearly  shown  in  the  repre- 
sentatives of  the  great  races  which  were  exhibited  a  moment  ago.  In 
fact,  the  only  difference  is  that  these  temperamental  types  are  further 
removed,  by  crossing,  from  their  racial  origin.  The  real  significance 
of  the  term  "pure  temperamental"  is  that  the  individual  instance 

13 


J.  Leon  Williams,  D.D.S. 

shows,  in  a  mixed  race,  an  unusual  reversion  to  the  dominant  racial 
type.  The  mixed  temperaments  are  simply  the  result  of  the  mingling 
of  the  blood  of  different  races,  somewhat  modified,  in  the  event  of  mi- 
gTation,  by  changed  environment. 

If,  therefore,  there  is  such  a  thing  as  a  sanguine  type  of  tooth 
or  a  bilious  type  of  tooth,  they  must  have  originated  in  the  sanguine 
and  bilious  races.  If  there  are  special,  characteristic,  temperamental 
forms  of  teeth,  there  must  have  been  racial  forms  from  which  they 
were  derived.  There  is  no  possibility  of  evading  the  logic  of  that 
conclusion.  And  I  think  it  has  always  been  assumed  by  our  profession 
that  there  are  racial  forms  of  teeth.  I  thinlc  you  will  find  many  refer- 
ences in  our  literature  to  this  supposed  fact. 

Now,  a  racial  form  of  tooth  must  mean  a  distinctive  form  pecul- 
iar to  a  race.  But  if  I  am  able  to  show  you  that  there  is  no  such 
thing  as  a  racial  form  of  tooth,  if  I  can  prove  beyond  all  possibility 
of  doubt  that  there  are  certain  primary  forms  of  teeth  which  are, 
in  their  general  type  characteristics,  common  to  all  races,  light  and 
dark,  ancient  and  modern,  savage  and  civilized,  then  I  submit  that 
even  the  unreasonable  minority  will  have  to  agree  that  all  belief  in 
a  temperamental  type  of  tooth  must  go. 

There  are  certain  differences  as  to  size  and  small  differences  in 
proportion  of  width  to  length  in  teeth  of  the  same  general  type  in 
different  races,  but  as  to  essential  differences  in  type,  there  are  none. 

^  ^  ^ 

When  I  began  my  work  of  investigating  the  forms  of  human 
teeth  at  the  Eoyal  College  of  Surgeons,  in  London,  it  was  with  the 
belief  that  there  were  racial  types  of  teeth.  I  had  no  doubt  about  it. 
I  had  so  often  seen  statements  to  that  effect  that  I  simply  assumed 
that  it  was  true.^  And  when  I  did  not  succeed  in  finding  any  form  of 
tooth  characteristic  of  race  I  concluded  that  my  failure  was  due  to 
race  admixture.  Even  with  the  most  sincere  desire  and  the  strongest 
determination  to  find  out  the  truth,  still  what  we  have  been  taught, 
our  inherited  beliefs,  will  continue  to  haunt  us  for  a  long  time,  like 
unhappy  ghosts  who  see  their  continued  existence  endangered  and  fight 
for  it  with  all  their  might.  I  pursued  this  study  for  nearly  a  year, 
and  during  that  time  I  was  accumulating  a  great  store  of  individual 
human  teeth.     The  largest  lot  that  reached  me  from  any  one  source 


"I  had  particularly  expected  to  find  strongly  marked  differences  between  the  teeth  of  the 
dolichocephalic  skulls  of  the  peoples  descended  from  the  Aryan  stock  and  those  of  the 
brachycephalic  skulls  representing  the  ancient  Mongolian  races.  I  also  expected  to  find  that 
the  teeth  of  remote  insular  groups,  such  as  the  Andamans,  Fijians  and  Tasmanians,  would 
present  strongly  marked  typal  features. 

14 


"A  !N"ew  Classificatioit  of  Tooth  Forms" 

came  from  tlie  University  of  Pittsburgli  by  the  kindness  of  Profes- 
sor Friesell.  But  for  this  interest  and  generous  action  on  his  part  I 
doubt  if  the  discovery  I  am  about  to  lay  before  you  would  have  been 
made.  One  day  it  occurred  to  me  that  it  v^ould  be  a  good  idea  to 
begin  sorting  and  arranging  the  central  incisors  into  groups.  (I  had 
long  seen  that  these  were  the  most  characteristic  of  human  teeth.)  As 
I  proceeded  in  the  work  it  became  evident,  after  a  time,  that  I  was 
accumulating  three  very  strongly  marked  groups  with  a  larger  num- 
ber partaking  more  or  less  of  the  combined  features  of  those  three 
groups,  but  generally  with  the  features  of  one  or  other  of  the  three 
groups  dominant  in  every  individual  tooth.  When  I  had  finished  ar- 
ranging my  incisors  in  this  way  I  again  went  to  the  Museum  of  the 
Eoyal  College  of  Surgeons  to  see  what  light  this  discovery  would 
throw  on  further  study  there.  I  w^as  more  than  a  little  surprised  to 
find  these  three  types  of  teeth  in  almost  every  group  of  skulls  which 
contained  a  dozen,  or  even  less,  with  the  incisor  teeth  intact.  My  long 
search  for  something  fundamental  had  been  rewarded.  I  had  at  last 
got  what  I  was  after — the  key  to  tooth  form.  All  along  I  had  seen 
that  there  were  different  types  of  teeth  in  all  the  different  races,  but 
the  co-relation  of  these  different  forms  had  never  struck  me  until  I 
went  there  with  the  knowledge  of  what  to  look  for.  That  is  generally 
the  way  with  all  discovery.  We  walk  unsuspectingly  over  gold  mines 
and  oil  wells  if  we  do  not  know  how  to  look  for  them.  When  I  saw 
clearly  that  these  three  types  of  teeth  existed  in  all  races,  I  knew 
instantly  that  I  had  got  Nature's  secret  of  design  in  human  teeth, 
and  I  knew  that  it  would  now  be  possible  to  beat  her  in  her  own  work ; 
for  jSTature,  working  more  or  less  blindly,  makes  endless  mistakes, 
as  I  have  previously  indicated,  while  we,  working  intelligently,  can 
avoid  those  mistakes.  I  saw  that  the  existence  of  three  types  of  teeth 
was  the  fundamental  fact  in  human  tooth  form  and  that  every  con- 
ceivable form  of  human  tooth  could  be  evolved  from  those  three  types, 
and  I  knew  that  it  would  be  possible  to  design  beautiful  and  anatomi- 
cally correct  forms  of  teeth  if  I  ever  saw  a  human  tooth  again. 

^  t^  t^ 

Let  us  now  examine  in  detail  the  proofs  of  the  statements  that 
JSTature  produced  three  typal  forms  of  teeth  in  all  races  and  modeled 
all  teeth  upon  these  three.  You  have  on  the  screen  a  photograph 
(Illustration  ISo.  6)  representing  a  small  but  representative  selection  of 
the  three  primary  forms  or  types  of  human  teeth.  In  all  reference  to 
them  they  will  be  designated  as  Class  I,  II,  and  III.  Class  I  is  character- 
ized by  the  parallel  or  nearly  parallel  lines  which  represent  the  proximal 

15 


J.  Leon  Williams,  D.D.S. 

surfaces  of  these  teeth  for  half  or  more  than  half  of  their  length  from 
their  incisal  edges.  In  Class  II  these  lines  converge  so  markedly  that 
they  would  meet  in  most  instances,  at  a  point  near  the  end  of  the  root. 
These  converging  lines  are  sometimes  nearly  straight,  but  usually 
there  is  a  very  slight  convexity  of  the  mesio-proximal  surface  and  a 
slight  concavity  of  the  distal  surface.  Class  III,  which  I  regard  as 
the  most  beautiful  form  of  human  teeth,  and  which  has  rarely  if  ever 
before  been  used  as  a  model  for  artificial  teeth,  is  characterized  by  a 
delicate  double-curved  line  on  its  disto-proximal  surface  and  some- 
times, though  less  frequently,  on  the  mesial  surface.  All  of  the  sur- 
faces and  angles  of  teeth  of  this  class  are  more  rounded  and  graceful 
than  in  either  of  the  other  two  classes.  The  specimens  shown  in  this 
photograph  represent  the  most  severe  or  typal  shapes  of  what  I  call 
the  primitive  forms  of  human  teeth.  My  reason  for  the  use  of  the 
word  "primitive"  will  appear  later.  All  of  the  other  teeth  in  any 
given  set  partake  of  the  features  of  the  central  incisors  but  to  a  much 
less  marked  degree.  But  in  this  respect  the  natural  teeth  of  a  given 
set  are  not  always  in  harmony.  The  crossing  of  races  or  some  other 
cause  often  disturbs  the  perfect  harmony  of  line  of  the  different  teeth 
in  a  set,  and  you  may  sometimes  find  centrals  of  one  class  and  laterals 
and  canines  of  another.  But  usually  the  harmony  is  more  or  less 
perfectly  preserved.  In  designing  artificial  teeth  we  can,  of  course, 
always  maintain  a  proper  harmony  throughout  and  thus  improve  on 
IN^ature.  The  succeeding  photographs  will  show  you  laterals  (Illustra- 
tion 'No.  T)  and  canines  arranged  in  the  order  of  the  three  classes.  As 
I  have  intimated,  the  class  characteristics  are  not  so  marked  in  these 
teeth  as  in  the  centrals,  but  you  will  have  no  diSiculty  in  seeing  in  any  of 
the  groups  something  of  the  special  features  of  each  type.  In  this 
photograph  you  see  the  effects  of  crossing  the  types.  There  is  more 
or  less  blending  of  the  primitive  forms,  although  in  nearly  every  in- 
stance the  dominance  of  one  type  or  another  can  be  perceived.  Prob- 
ably the  majority  of  teeth  in  all  mixed  races  are  of  this  character. 

•^  'ife  ««fe 

We  wiU  now  pasS  to  an  examination  of  the  teeth  of  some  of  the 
more  important  civilized  and  savage  races  of  ancient  and  modern 
times,  in  which  I  shall  show  you  that  the  three  types  or  classes  of 
teeth  I  have  illustrated  and  described  are  to  be  seen  in  the  skulls  of 
all  these  otherwise  widely  divergent  peoples.  In  this  first  exhibit, 
the  skulls  will  all  be  shown  in  groups  of  three,  thus  presenting  in  one 
view  the  three  primitive  forms  of  teeth  in  each  race.  We  will  begin 
^ith  three  skulls  from  a  savage  race  of  to-day — the  Sandwich  Islanders 

16 


Illustration  No.   6 
Three  classes  of  centrals.     Class  I  upper  row;   Class  II  middle  row;  Class  III  lower  row 


Illustration  No.   7.     Three  classes  of  laterals.     Arranged  like  centrals  above 


"A  ISTew  Classification  of  Tooth  Forms" 

(Ulustration  ISTo.  8).  The  shape  of  the  skulls  differ  markedly,  but  this 
difference  in  skull  shape  has  no  necessary  relation  to  the  different  forms 
of  teeth.  We  have  here  the  three  primary  forms  of  human  teeth  very 
clearly  shown.  We  have  the  square  tooth  with  parallel  sides  in  skull  ]^o. 
1,  the  pyramidal  shaped  tooth  with  its  converging  lines  in  JSTo.  2,  and 
an  ideal  specimen  of  Class  III,  with  its  beautiful  curves  in  skull  No. 
3. 

As  you  would  expect,  not  all  of  the  teeth  in  the  different  groups 
of  skulls  which  I  shall  exhibit  are  such  perfect  examples  of  the  severer 
forms  of  the  three  classes.  Probably  perfect  examples  could  always 
be  found  if  one  had  a  sufficiently  large  number  of  skulls  at  command. 
The  surprising  thing  is  that  even  in  a  small  collection  of  skulls,  often 
less  than  a  dozen,  I  have  always  been  able  to  find  fairly  good  represen- 
tatives of  the  three  classes,  but  I  believe  that  the  more  severe  typal 
forms  are  more  frequently  found  in  those  races  in  which  there  has 
been  the  least  crossing. 

The  next  view*  is  of  three  Javanese  skulls.^  Here  the  centrals  in 
Class  III  have  been  slightly  modified  toward  the  oval  form:  Class  II 
is  well  represented  by  the  pyramidal  shaped  teeth  in  skull  ISTo.  2,  and 
'No.  1  shows  a  very  good  example  of  Class  I. 

Here  we  have  three  skulls  from  another  ancient  civilized  race — 
the  Chinese.  No.  1  shows  a  slightly  modified  form  of  the  typal  tooth, 
but  ISTos.  2  and  3  are  excellent  representatives  of  their  respective 
classes. 

«<fe  *%  -^ 

The  next  group  shows  two  skulls  of  the  modern  German.  I  was 
unable,  in  the  small  collection  of  skulls  at  my  command,  to  find  a 
good  example  of  No.  3  in  this  series.  It  should  be  said  that  the  photo- 
graphs, in  many  instances,  do  not  show  the  characteristics  of  the  dif- 
ferent forms  of  teeth  as  clearly  as  they  would  be  seen  in  handling  the 
skulls. 

Three  modern  Greek  skulls  are  shown  in  this  view — 1  and  2 — 
very  good  examples  of  their  class,  ]^o.  3  somewhat  modified  in  the 
direction  of  2, 

Skulls  of  modern  Hindoos — all  excellent  specimens  of  their  re- 
spective types. 

Three  strongly  marked  forms  of  Patagonian  teeth — l^o.  1  very 
slightly  modified  toward  the  oval  shape;  ITo.  2  typical  and  ISTo.  3  an 
interesting  modification  in  which  the  line  of  double  curve  appears  on 
both  mesial  and  distal  surface. 


*It  is  not  possible  to  reproduce  here  all  the  slides  shown. 

^I    do    not   think   that    these    skulls    represent    the    true    aboriginal    natives    of    Java.      They 
are  probably  those   of  a  mixed  race. 

17 


J.  Leon  Williams,  D.D.S. 

A  group  from  the  New  Hebrides.  IsTos.  2  and  3  are  perfect  ex- 
amples of  their  classes,  while  No.  1  is  slightly  modified  in  the  direc- 
tion of  Class  III.    Notice  the  wide  divergence  in  shape  of  these  skulls. 

These  are  three  Spanish  skulls.  I  had  a  rather  poor  collection 
to  select  from  in  this  group.  But  they  are  interesting  in  their  way. 
They  all  represent  modifications  of  the  three  primitive  forms  of  teeth 
and  might  be  called  secondary  types  with  the  primary  form  dominant 
in  each  specimen.  No.  3  is  especially  interesting  as  it  represents  a 
form  of  tooth  of  decided  character  frequently  met  with.  The  con- 
verging lines  of  the  type  are  somewhat  rounded  or  curved,  the  mesial 
line  always  more  sloping  than  the  distal.  There  is  nearly  always  slight 
overlapping  with  this  form  of  central. 

French  skulls.  Classes  II  and  III  well  represented.  Class  I  shows  a 
coarse  modification  of  the  typal  form. 

These  three  from  the  West  coast  of  Africa — all  fine  characteristic 
examples,  although  No.  3  is  somewhat  marred  by  the  filing  of  the 
centrals. 

Three  specimens  from  Italy.  Nos.  1  and  3  typical.  No.  2  modi- 
fied. 

A  group  from  the  Fiji  Islands  (Illustration  No.  9).  Please  observe 
that  when  the  teeth  are  not  all  good  examples  of  the  primary  forms  of 
their  class,  yet  the  variation  in  form  is  so  great  as  to  completely  upset 
the  theory  of  a  racial  type  of  tooth. 

Two  Kaffir  skulls.  Perfect  examples  of  classes.  The  next  two 
and  three  groups  of  skulls  are,  in  some  ways,  the  most  interesting  in 
the  entire  collection  shown  you  to-night.  The  natives  of  Australia 
(Illustration  No.  10),  Tasmania  (Illustration  No.  11)  and  New  South 
Wales  represent  the  lowest  type  of  human  beings  of  modern  times.  The 
skulls  of  these  savages  have  many  points  of  resemblance  to  the  Anthro- 
poid Apes.  Here,  if  anywhere,  you  might  expect  to  find  a  racial  form 
of  tooth.  But  just  observe  the  difference  in  the  shape  of  these  skulls  and 
teeth.  With  the  exception  of  the  teeth  of  the  ancient  Egyptians,  these 
low  Australian  savages  exhibit  the  characteristics  of  the  three  primitive 
forms  or  types  of  teeth  more  clearly  than  any  others  in  the  groups 
I  have  shown.  No.  3  is,  I  believe,  regarded  as  one  of  the  greatest 
anatom-ical  treasures  of  the  Museum  of  the  Royal  College  of  Sur- 
geons. It  probably  shows  more  intimate  relationship  with  the  Anthro- 
poid Apes  than  any  other  modern  skull.  It  was  received  from  Aus- 
tralia just  as  I  was  finishing  this  work  of  investigation  and  was  photo- 
graphed for  the  first  time  for  me. 

18 


Illustration  No.   8.     Sandwich  Islanders,   showing  three  classes  of  teeth 
In  all  the  following  illustrations,  Class  I  is  shown  on  the  left  and  Class  III  on  the  right 


Illustration  No.  9.     Fiji  Islanders — varying  tooth  forms  in  same  race 


"A  JSTew  Classificatiojst  of  Tooth  Forms" 

The  last  group  in  this  series  that  I  shall  show  you  (Illustration 
ISTo.  12)  is  from  that  very  interesting  ancient  race,  the  Egyptians  of  the 
III  and  TV  dynasties — a  period  dating  more  than  2,000  years  before 
Moses  led  the  Children  of  Israel  out  of  Egypt.  We  are  back  in  the 
Bronze  Age  at  the  dawn  of  what  we  call  civilization,  the  time  of  the 
Troy  of  the  Iliad  and  before  the  Great  Pyramid  was  built.  It  was  a  piece 
of  great  good  fortune  to  have  found  three  such  perfect  skulls  from  this 
far  distant  era,  showing  so  perfectly  the  three  primary  types  of  teeth. 
They  are  each  ideal  specimens  of  their  class.  The  teeth  in  skull  IsTo. 
1  answer  perfectly  to  the  description  given  in  our  text  books  of  the 
sangTiine  type  of  tooth,  but  I  believe  all  authorities  are  agreed  that 
those  ancient  Egyptians  did  not  have  light  hair  or  blue  eyes  or  a 
ruddy,  light  skin.  There  is  evidently  a  mistake  somewhere — perhaps 
it  is  the  fault  of  the  Egyptians.  But  the  forms  of  teeth  shown  in  the 
other  two  skulls  have  never  been  observed  by  any  advocate  of  the 
temperamental  theory  of  classification.  ]^ew  temperaments  will  have 
to  be  invented  for  them. 

Suppose  the  teeth  in  all  three  of  these  skulls  had  been,  as  might 
easily  have  happened,  of  type  I,  a  strong  tooth  full  of  character.  Would 
it  not  have  been  said  that  here  was  the  typical  racial  tooth  form  of 
the  ancient  Egyptians  ?  This  mistake  concerning  racial  types  of  teeth 
has  gTown  out  of  insufficient  critical  observation. 

'^  '^  '^ 

I  think  a  little  diversion  from  our  main  theme,  just  to  relieve  the 
mental  tension  for  a  moment,  may  be  acceptable.  The  most  of  you 
probably  know  that  these  ancient  Egyptian  kings  had  what  you  might 
call  supplementary  names — a  sacred  name,  and  also,  at  least,  some- 
times, a  name  taken  or  given  them  for  some  accomplishment  and 
characteristic  quality.  ISTow  the  name  of  one  of  the  kings  of  the  period 
represented  by  these  skulls  was  Sneferu  or  Snefru.  According  to 
one  eminent  authority  the  English  interpretation  of  his  sacred  name 
was  "he  who  makes  good."  That  expression,  you  see,  is  not  quite  so 
modern  as  you  may  have  thought  it.  And  Snefru  also  had  another 
name  bestowed  upon  him  for  his  prowess  in  dealing  with  his  enemies. 
He  was  known  as  "the  wielder  of  the  big  stick" — that  expression,  too, 
was  not  invented  yesterday.  To  prove  to  you  that  I  am  not  romanc- 
ing in  this  matter  I  show  you  a  picture  of  Snefru  that  is  sculptured 
on  the  rock  walls  of  the  Wady-Maghara  near  Sinai.  There  he  stands, 
club  in  hand,  over  his  fallen  foe. 

19 


J.  Leon  Williams,  D.D.S. 

To  exliibit  in  another  striking  way  how  teeth  of  the  different 
types  or  chisses  run  through  all  the  widely  divergent  races,  I  have 
arranged  a  few  photographs  in  pairs.  The  full  meaning  of  what  I 
have  to  show  you  will  be  more  vividly  presented  if  1  exliibit  before 
each  group  of  teeth,  portraits  of  individuals  of  the  race  represented 
by  the  skulls  showing  the  teeth.  You  will  thus  have  in  mind  at  the 
moment  a  clear  picture  of  the  wide  divergence  of  races  in  which  there 
is  a  substantial  identity  of  tooth  form.* 

And  I  may  as  well  mention  right  here  that  the  practical  signifi- 
cance of  these  facts  is  that  they  demonstrate  and  prove  that  a  system 
of  artificial  teeth  designed  with  a  knowledge  of  all  the  facts  about  the 
human  teeth  is  equally  suitable  for  all  the  races  of  the  earth.  It 
covers  the  whole  held  and  that  has  never  been  done  before. 

Our  first  group  is  a  native  of  the  JSTew  Hebrides  and  a  modern 
Spaniard.  At  first  thought  it  seems  almost  incredible  that  any  two 
individuals  of  races  so  far  apart  in  racial  characters  should  have  teeth 
that  are  practically  identical.  But  the  two  skulls  now  sho^vn  on  the 
screen  prove  to  you  that  such  is  the  fact.  The  centrals  and  laterals 
in  both  are  of  precisely  the  same  type. 

Hfe  «^  '^ 

We  have  shown  here  a  Hindoo  and  a  Javanese  as  widely  diver- 
gent in  outward  appearance  as  the  Spaniard  and  the  New  Hebridean. 
But  when  we  look  at  the  skulls  of  representatives  of  these  two  races 
we  find  again  identity  of  tooth  form.  The  teeth  of  the  Javanese  are 
slightly  worn,  but  they  are  otherwise  the  same  in  form  and  size. 

In  this  view  we  have  a  native  Australian  and  a  woman  of  Ger- 
many. It  is  not  necessary  to  call  attention  to  the  striking  contrast 
of  these  faces. 

But  what  about  the  teeth  in  these  two  examples?  You  see  a 
striking  difference  in  the  size  and  form  of  the  skull,  but  the  teeth  are 
identical  in  type — both  being  fine  specimens  of  Class  II. 

A  modern  Chinese  and  a  Patagonian. 

Here  also  the  teeth  in  both  skulls  are  of  Class  II,  but  in  this  in- 
stance those  of  the  Patagonian  are  slightly  larger,  the  laterals  markedly 
so. 

In  these  two  portraits  we  probably  have  as  strong  a  contrast  in 
physiognomy  as  could  be  found  in  any  two  human  races  that  have  ever 
inhabited  our  earth.  In  looking  at  this  portrait  of  one  of  the  last  of 
the  Tasmanians,  a  race  that  has  only  recently  become  extinct,  one 
cannot  fail  to  be  struck  with  the  striking  resemblance  of  the  nose  and 
mouth  to  those  same  features  in  the  chimpanzee. 

*It  is  impossible  to  here  reproduce  these  photographs  of  individuals. 

20 


Illustration   No.    10.     Natives  of  Australia 


Illustration   No.    11.      Natives   of   Tasmania 


Illustration   No.    12.     Ancient   Egyptians,   showing  three   primary   tj'pes   of   tooth   forms 


Illustration  No.   13 

Eight  skulls  of  unlike  size  and  form.  All  exhibit  teeth  of  Class  III.  The  form  and  size  ot 
the  teeth  bear  no  relation  to  the  form  or  size  of  the  skull. 

Nationalities  from  left  to  right  are: 

Australian,  Sandwich  Islander,  Ancient  Egyptian,  Kaffir,  Chinese,  African  Savage,  New 
Hebridean,   Hindoo. 


"A  New  CLASsiFiCATioisr  or  Tooth  Forms" 

But  wlien  we  look  at  the  skulls  from  these  two  races  we  see  that 
in  the  teeth  all  contrast  has  disappeared.  Here,  indeed,  we  have  the 
one  physical  touch  of  l^ature  that  makes  the  whole  world  not  only 
akin,  but  of  one  family.  I  shall  have  time  to  show  you  but  one  more 
illustration  of  the  identity  of  tooth  form  in  different  races,  but  in  this 
group  I  will  give  three  examples — a  Kaffir,  an  Egyptian  and  a  native 
of  the  Sandwich  Islands. 

You  see  a  striking  difference  in  size  and  shape  of  skull,  but  identity 
in  type  of  tooth,  and  but  very  little  difference  in  size. 

Let  me  now  call  your  attention  to  two  views  which  present  a  still 
stronger  proof  of  the  fallacy  of  the  racial  type  theory. 

You  have  on  the  screen  a  photograph  of  eight  skulls  (Illustration 
"No.  13),  representing  eight  different  races  as  different  in  physiognomy, 
^hape  and  size  of  skull  and  general  race  characters  as  it  is  possible  to  find. 
The  central  incisors  are  all  of  one  type — Class  III — the  form  of  tooth 
that  has  never  before  been  observed.  In  this  next  view  you  have  nine 
more  skulls  (Illustration  ISTo.  14),  all  from  different  races,  and  in  these 
you  have  another  distinct  type  of  tooth,  that  of  Class  I  with  slight  varia- 
tions, and  this  form  also,  you  see  is  common  to  all  the  races. 

While  the  view  of  a  considerable  number  of  skulls  is  before  you 
I  will  once  more  ask  you  to  note  the  fact  mentioned  several  times, 
during  the  course  of  this  lecture,  that  ]N"ature  does  not  always  produce 
a  definite  type  of  tooth  for  any  given  form  of  skull. 

*%  '^  *<& 

During  life,  the  individuals  which  these  skulls  represent  must 
have  presented  a  great  variety  of  facial  contours.  But  observe  how 
many  of  the  central  incisors  in  these  widely  varying  skulls  are  alike  or 
nearly  so.  Look  at  that  upper  row  of  four  skulls.  The  teeth  are 
identical  in  type  and  nearly  so  in  size.  But  what  a  contrast  in  the 
skulls,  especially  in  1448  and  398,  and  again  you  see  the  smaller  skuU 
has  slightly  larger  teeth. 

Some  of  you  may  be  thinking  that  I  specially  selected  these  speci- 
mens from  a  very  large  collection  of  skulls.  But  I  did  not ;  I  took  what  I 
already  had  in  hand  for  other  purposes.  They  are  simply  different 
groupings  of  those  which  were  first  shown  on  the  screen. 

Again  I  say  the  proof  that  Nature  produces  no  perfect  harmonies 
of  relationship  in  the  different  parts  of  organisms  is  to  be  seen  on 
every  hand.     It  is  before  our  eyes  all  the  time. 

In  bringing  forward  so  many  of  these  contradictions  of  Nature, 
I  may  seem  to  be  introducing  an  unnecessary  confusion.  But  what  I 
am  really  trying  to  do  is  to  bring  order  out  of  confusion.     And  in  any 

21 


J.  Leon  Williams,  D.D.S. 

event  I  think  it  is  always  much  better  to  know  and  face  all  of  the 
important  facts  in  any  problem,  but  I  hope  no  one  will  take  the  demon- 
strations and  facts  I  have  just  presented  as  warranting  the  conclusion 
that  natural  teeth  are  always  so  imperfectly  adapted  to  face  and  fea- 
tures, that  this  relationship  may  be  neglected.  That  would  be  as  far 
from  the  truth  as  the  assumption  that  l^Tature  always  produces  a  per- 
fect harmony  between  teeth  and  face.  The  important  point  which 
contains  the  gist  of  the  whole  matter  is  simply  this:  there  is  such  a 
considerable  minority  of  cases  in  all  mixed  races,  especially  in  all 
widely  divergent  races  in  which  crossing  has  recently  occurred,  in 
which  there  is  more  or  less  disharmony  in  the  relation  of  features, 
that  it  would  be  a  disastrous  mistake  either  to  found  a  system  of  arti- 
ficial teeth  on  the  assumption  that  all  natural  teeth  are  in  harmony 
with  the  organism,  or  to  conclude  that  in  edentulous  cases  no  improve- 
ment over  the  natural  teeth  which  the  patient  had  is  ever  possible. 

More  than  that,  I  will  say  that  anyone  who  wall  take  the  trouble 
to  examine  and  compare  forty  or  fifty  skulls  from  almost  any  race  will 
be  forced  to  the  conclusion  that  if  he  wishes  to  follow  Nature  blindly 
in  the  matter  of  adapting  teeth  to  facial  contour  he  has  a  fairly  wide 
range  of  choice  in  making  his  selection.  It  would  probably  express 
an  important  truth  to  say  that  ligature  seems  to  be  always  striving  to 
reach  or  realize  harmony,  but  rarely  achieving  a  perfect  success,  and 
sometimes  going  very  wide  of  the  mark.  The  great  variety  of  incon- 
sistencies in  J^ature  emphasizes  in  a  most  striking  manner  the  para- 
mount importance  of  finding  some  fixed  principle  of  harmony  between 
tooth  form  and  facial  contour.  Art  must  supply  us  with  that  which 
Nature  has  failed  to  give  us.  What  we  have  to  do  is  to  study  closely 
the  majority  of  instances  in  which  an  approximation  to  harmony  is 
seen,  and  from  the  knowledge  thus  gained  to  deduce  the  general  prin- 
ciples on  which  the  highest  possible  degree  of  success  may  be  based. 
No  clear,  definite  statement  of  such  principles  is  to  be  found  anywhere 
in  our  literature. 

'^  '^  '^ 

The  one  important  fact  we  have  established  up  to  this  point  is 
that  there  are  three  types  of  teeth  common  to  all  races. 

I  have  no  need  to  labor  this  point  of  identity  of  tooth  form  in 
different  races  or  to  press  for  conclusions  in  the  least,  beyond  what  the 
facts  will  fully  warrant,  but  I  submit  that  I  have  destroyed  the  last 
vestige  of  a  belief  in  a  racial  type  of  tooth.  And  along  with  the 
passing  of  that  belief  there  must  disappear  also  the  theory  of  a  tem- 
peramental type  of  tooth.     My  summary  of  the  whole  matter  is  this: 

22 


Illustration  No.    14 

Nine  skulls  of  different  races  and  unlike  size  and  contour,  all  with  teeth  of  Class  I.  The 
form  and  size  of  the  teeth  bear  no  relation  to  the  form  or  size  of  the  skull. 

Nationalities  from  left  to  right  are: 

Spanish,  Sandwich  Islanders,  New  Hebridean,  German,  Javanese,  Hindoo,  Fiji  Islander, 
Italian,  Ancient  Egyptian. 


"A  [N'ew  CiiAssiFiCATioisr  OP  Tooth  Tokms" 

That  as  a  working  theory  it  has  always  been  so  vague  in  statement  and 
indeterminate  in  application  that  it  has  never  taken  any  serious  hold 
upon  dentists  and  is  practically  a  dead  letter  with  more  than  nine- 
tenths  of  the  profession;  that  to  teach  a  theory  which  no  one  really 
practices  or  understands  is  immoral,  because  it  leads  directly  to  a 
disbelief  in  any  scientific  basis  for  prosthetic  dentistry;  that  if  there 
had  ever  been  any  real  desire  to  undertake  a  practical  application  of 
the  theory  it  would  not  have  been  possible  to  do  so  because  no  manu- 
facturer of  artificial  teeth  has  ever  made  any  successful  attempt  to 
comply  with  the  demands  of  the  theory;  and  lastly,  that  the  theory 
has  absolutely  no  foundation  in  scientific  fact,  because  it  is  fully  and 
incontrovertibly  demonstrated  that  any  given  forms  of  teeth  are  not 
peculiar  to  any  race,  neither  do  they  bear  any  necessary  relation  to 
the  shapes  or  sizes  of  skulls.  In  all  races  there  is  community  o£  typal 
tooth  form.  Small  variations  in  size  and  small  variations  in  propor- 
tion of  width  to  length  there  certainly  are  in  the  teeth  of  different 
races,  but  the  three  types  or  classes  are  present  and  distinct  in  all  the 
races  I  have  examined.  In  fact,  one  of  the  most  interesting  things  to 
me  in  the  course  of  this  investigation  has  been  to  see  how  the  three 
types  everywhere  persist  through  the  small  variations  observable  in 
the  teeth  of  different  races.® 

'^  *<&  *% 

Although  just  a  little  aside  from  our  main  subject,  I  think  it  will 
interest  you  to  have  a  glance  at  a  few  prehistoric  skulls  (Illustration  ^o. 
16).  The  three  now  shown,  reading  from  your  left  to  your  right,  are 
known  to  anthropologists  as  the  man  of  La-Chapelle-aux-Saints,  a  typical 
skull  of  the  very  ancient  J^eanderthal  race,  the  Coombe  Capelle  man, 
representing  the  Aurignacian  race,  and  the  "old  man  of  Cro-Magnon,"  a 
representative  of  the  race  of  the  same  name.  Their  estimated  ages 
range  from  25,000  to  150,000  years.  I  believe  no  prehistoric  skull 
has  been  discovered  with  an  over  bite  of  the  upper  incisors.  The  two 
shown  on  the  right,  you  see,  have  the  edge-to-edge  bite.  The  third 
one,  the  man  of  La-Chapelle-aux-Saints,  must  have  been  a  very  aston- 
ishing and  savage  looking  creature  with  a  very  projecting  muzzle,  huge, 
flat  nose,  enormous  eye  sockets  and  heavy  supra-orbital  ridges.  Ob- 
serve that  his  teeth  were  nearly  all  lost  from  loosening  and  decay. 
This  skull  is  also  from  the  Cro-Mag-non  race.  ISTotice  the  great  depth 
of  the  lower  jaw  and  the  size  of  the  central  incisors,  which  are  fine 


^Keane,  in  his  table  of  Ethnology,  describes  the  teeth  of  the  negro  races  as  large  (macro- 
dont),  those  of  the  Mongols  and  native  Americans  as  medium  (mesodont)  and  the  Caucasian 
teeth  as  small   (microdont).     But  the  teeth  of  the  mixed  races  range  through  all  these  sizes. 

23 


J.  Leon  Williams,  D.D.S. 

specimens  of  Class  I.  I  have  another  skull  of  the  same  race  in  which 
the  teeth  are  of  a  totally  different  type — approaching  Class  III — with 
rather  small  and  very  beautifully  modeled  teeth. 

The  next  slide  and  the  following  one*  show  a  peculiarity  or  a 
specialization  of  the  teeth  of  the  Xeanderthal  race,  which  enables  us 
to  recognize  this  ancient  people  whenever  teeth  of  this  type  are  dis- 
covered. This  peculiarity  is  twofold — fusion  of  the  roots  and  enor- 
mous size  of  pulp  cavity. 

This  photograph  shows  the  efforts  of  three  different  artists,  all 
trained  anthropologists,  to  represent  different  types  of  prehistoric  races. 

Let  me  now  call  your  attention  to  another  discovery  I  have  made, 
in  relation  to  what  has  already  been  shown,  that  is  not  only  interest- 
ing to  us  as  dentists,  but  has  also  proved  to  be  of  deep  interest  to 
anthropologists  and  workers  in  other  scientific  fields.  The  significance 
of  this  discovery  is  that  it  traces  the  origin  of  these  three  types  of  teeth 
back  to  a  time  antecedent  to  the  advent  of  humanity.  When  I  had 
made  thorough  examination  of  the  teeth  of  the  lowest  and  most  primi- 
tive races,  finding  everywhere  the  three  distinct  forms,  it  occurred 
to  me  one  day  that  the  teeth  of  the  anthropoid  apes  might  throw  some 
light  on  this  question  of  origin  of  types.  You  now  have  on  the  screen 
a  photograph  (Illustration  ISTo.  16)  of  three  skulls  of  the  orang-outang. 
I  have  selected  these  as  representing  the  group  of  anthropoid  apes  be- 
cause the  teeth  in  these  three  skulls  were  the  most  unworn  and  perfect 
available  at  the  moment,  but  the  facts  are  the  same  with  reference  to 
the  gorilla  (Illustration  jSJ'o.  17)  and  the  chimpanzee  (Illustration  'No. 
18). 

«%  '^  <^ 

You  will  observe  that  we  have  here  the  three  types  of  teeth  that 
we  have  seen  in  all  the  races  shown,  but,  as  you  would  expect,  the 
characteristics  of  each  are  rather  more  strongly  marked  than  in  the 
genus  Homo.  You  have  the  central  incisor  with  parallel  sides,  the- 
representative  of  Class  I,  the  incisor  with  sharply  converging  sides  of 
Class  II,  and  the  one  with  the  fine  double  curve  on  its  distal  side  and 
the  generally  rounded  form  which  is  the  special  feature  of  Class  III. 
If  there  is  any  temperamental  sig-nificance  in  these  forms  of  teeth  in 
the  anthropoid  apes,  I  should  be  glad  to  have  it  pointed  out. 

Another  very  significant  fact  in  this  connection  is  that  in  the 
anthropoid  apes  the  variation  in  the  proportion  of  width  to  length 
of  the  central  incisors  in  Class  I  is  very  marked,  some  being  very 
short  and  others  very  long,  while  in  the  other  t^vo  classes  this  varia- 
tion is  very  slight.     Exactly  the  same  thing  is  true  of  himian  teeth. 

'These  illustrations  are  not  available  for  use  at  the  time  this  book  goes  to  press. 

24 


Illustration  No.   13.     Prehistoric  skulls.     Xeander  that  at  the  left 


"A  'New  Classificatiojst  of  Tooth  Foems" 

It  is  for  this  reason  that  Class  I,  in  our  system,  has  a  series  of  three 
lengths  with  five  sizes  to  each  length,  while  the  forms  in  the  other 
two  classes  are  produced  in  series  of  sizes  only,  or  with  but  slight 
variation  in  proportion  of  width  to  length. 

Whatever  the  ancestral  form  may  be  from  which  man  and  the 
anthropoid  apes  have  descended,  or  ascended,  it  is  plain  that  we  have 
here  one  of  the  most  striking  homologies  that  has  been  discovered.  It 
is  an  especially  interesting  evidence  of  relationship  because  it  is  one 
of  Owen's  classical  examples  of  homology  and  analogy.^° 

The  teeth  are  still  functional  in  both  man  and  the  apes.  It  is 
clear,  therefore,  that  the  origin  of  the  three  types  of  human  teeth  can 
be  traced  back  into  what  the  old-fashioned  orator  was  fond  of  refer- 
ring to  as  "the  dim  mists  of  antiquity."  We  have  reached  something 
fundamental  here  that  is  of  very  great  importance  in  our  work.  Man 
has  three  types  of  teeth  because  they  have  been  bequeathed  to  him 
from  his  simian  ancestors,  just  as  he  has  five  fingers  and  five  toes,  be- 
cause they  have  been  passed  on  to  him  from  the  early  amphibians. 
You  now  understand  why  I  call  the  three  severe  types  or  classes  of 
human  teeth  the  "primitive"  forms. 

'^  '^  '^ 

It  may  interest  you  to  know  that  this  discovery  of  the  funda- 
mental types  of  teeth  in  man  and  the  anthropoid  apes  as  shown  in, 
these  photographs,  has  been  submitted  to  quite  a  number  of  the  fore- 
most scientific  men  of  the  United  States  and  Europe,  among  whom 
I  may  mention  Prof.  Henry  Fairfield  Osborn,  President  of  the  Amer- 
ican Museum  of  ISTatural  History,  Professor  Schafer  of  Edinburgh, 
President  of  the  British  Association  of  Science  for  1912;  Professor 
Keith,  Hunterian  Lecturer  at  the  Poyal  College  of  Surgeons,  and 
author  of  "Types  of  Ancient  Man" ;  Dr.  Woodward,  of  the  ISTatural 
History  Museum,  South  Kensington;  Dr.  A.  Russell  Wallace,  co- 
discoverer  with  Darwin  of  the  principle  of  ISTatural  Selection,  and 
Prof.  Ernst  Haeckel,  of  the  University  of  Jena,  admittedly  the  great- 
est authority  who  has  ever  lived  in  matters  of  comparative  morphology 
in  man  and  the  lower  animals.  It  was  of  Professor  Haeckel's  great 
work  on  morphology  that  Huxley  said:  "It  is  one  of  the  greatest  pro- 
ductions in  the  history  of  science."  And  Darwin  said  that  if  he  had 
read  Haeckel's  "Comparative  Morphology"  before  he  began  the  "De- 
scent of  Man,"  that  book  would  never  have  been  written. 

^""The  wing  of  a  bird  and  the  wing  of  a  bat;  they  are  both  fore-limbs  of  similar  structure 
and  development;  they  are  both  organs  of  true  flight;  they  are  at  once  homologous  and  analo- 
gous."— Owen. 

"When  two  or  more  structures,  organs  or  specialized  parts,  in  one  and  the  same  organism, 
or  in  several  organisms,  show  a  deep  resemblance  in  their  architecture  and  also  in  their 
manner  of  development,  they  are  said  to  be  homologous.  .  .  .  Now,  the  evolutionary 
suggestiveness   of   homologies   is  indisputable." — Evolution,   by   Thomson   and    Geddes. 

25 


J.  Leon  Williams,  D.D.S. 

Very  interesting  comments  have  been  made  and  no  word  of  criti- 
cism has  been  passed  on  what  seems  to  be  the  inevitable  conclusion  of 
the  facts  shown  in  my  photographs.  But  as  the  discovery  was  in  the 
field  of  comparative  morphology  it  was  Professor  Haeckel's  opinion 
that  I  particularly  desired. 

I  think  the  letter  conveying  that  opinion  to  me  is  sufficiently 
characteristic  and  interesting  to  warrant  publication. 

He  says: 

Jena,  6,  1,  1913. 

Dk.  Leon  Williams^ 
London. 
Dear  Sir. — Your  observations  on  the  three  different   types   of 
the  upper  central  incisors  are  very  interesting,  and  mainly  the  fact 
that  the  same  three  characteristic  types  occur  also  in  the  orang-outang 
and  in  other  anthropoid  apes.     In  my  opinion  this  fact  is  another 
new  and  convincing  proof  for  the  near  relationship  between  man  and 
the  anthropoid  apes,  and  for  the  phylogenetic  theories  that  both  have 
been  derived  from  one  and  the  same  common  ancestor.      First,   the 
fact   that   these   three   types — in   physiological    relationship    of   little 
value — are  so  distinctly  developed  in  three  morphological  directions, 
seems  to  me  an  important  proof  that  the  way  of  phylogenetic  diver- 
gence of  characters  is  the  same  in  man  and  in  the  anthropoid  apes. 
Very  respectfully  yours, 

(Signed)     Ernst  Haekel. 

"With  what  admirable  clearness  and  conciseness  Professor  Haeck- 
el's masterful  mind  has  gone  straight  to  the  mark  in  that  letter. 
Three  forms  or  types  of  teeth  have  no  special  physiological  signifi- 
cance, as  he  says.  One  type  is  as  good  as  another  for  purposes  of 
mastication.  But  the  morphological  meaning  conveys  the  story  of 
man's  origin,  and  so  becomes  one  of  the  most  fundamental  facts  about 
human  teeth.  x\nd  on  that  fundamental  fact  is  established  the  new 
classification.^^ 

I  have  several  times  intimated  during  the  course  of  this  paper 
that  the  makers  of  artificial  teeth  have  never  had  any  scientific  guid- 
ing principle  either  for  classification  or  design.  Let  me  finish  with 
that  subject  now,  and  I  will  then  take  up  the  constructive  part  of  my 
work.  What  have  the  manufacturers  done  when  they  have  wished  to 
produce  a  new  pattern  of  their  so-called  natural  form  teeth?     They 


""In  connection  with  the  skull,  I  may  speak  of  the  teeth-organs  which  have  a  peculiar 
classificatory  value,  and  whose  resemblances  and  differences  of  number,  form  and  succession, 
.taken  as  a  whole,  are  usually  regarded  as  more  trustworthy  indicators  of  affinity  than  any 
-others."     Man's  Place  in  Nature,  Huxley.     The  italics  are  mine. 

26 


Illustration  No.    16.      Skulls  of  orang-outang,  showing  three  primary  tooth   forms 


Illustration   No.    17.     Three  types  in  skulls   of  gorilla 


Illustration  No.   18.     Chimpanzee   Skulls 


"A  'N:ew  Classification"  of  Tooth  Foems" 

have  looked  about  until  tiiej  found  what  they  considered  a  particu- 
larly attractive  looking  set  of  teeth,  either  in  a  skull  or  in  the  mouth 
of  some  living  person,  and  have  then  copied  this  set  of  teeth  as  well 
as  they  could.  Well,  that  work  is  a  long  step  in  advance  of  the  old 
products  of  the  tooth  factories.  But  for  whom  are  those  teeth  suit- 
able in  artificial  dentures  ?  On  the  assumption  that  in  iSTature  a  set 
of  teeth  is  in  perfect  harmony  with  the  face  and  features,  that  par- 
ticular set  of  teeth  could  not  possibly  be  in  perfect  harmony  with  a 
different  face.  But  I  have  called  your  attention  to  the  fact  that  should 
always  have  been  obvious  to  us,  viz.,  that  in  ISTature  there  is  rarely 
more  than  approximations  to  harmony  and  often  such  a  lack  of  har- 
mony that  the  grotesque  is  suggested.^' 

'^  '^  '^ 

If  the  set  of  teeth  copied  was  not  in  harmony  with  the  skull  or 
the  face  in  which  they  were  found,  what  suggestion  has  ever  been 
made  for  their  harmonious  use?  When  the  manufacturer  wishes  to 
produce  another  mould  he  finds  another  set  of  teeth,  and  for  a  third 
mould  a  third  set  of  teeth,  and  so  on,  ad  infinitum.  As  the  minute 
variations  in  natural  teeth  are  probably  only  limited  by  the  number 
of  people  dead  and  living  and  to  be  born,  is  there  any  good  reason 
why  the  manufacturers  should  not  go  on  to  the  end  of  time  produc- 
ing new  moulds  of  teeth?  And  have  they  not  always  acted  on  that 
principle  ?  Have  not  all  the  companies  in  existence  been  turning  out 
new  moulds  of  teeth  steadily  for  nearly  a  century?  Working  accord- 
ing to  their  present  plan,  is  there  any  reason  why  they  should  ever 
stop?  What  is  the  relation  between  the  teeth  of  one  manufacturer 
and  another?  There  is  none  except  when  they  copy  each  other's 
patterns,  which  they  frequently  do.  ISTor  is  there  any  ordered  rela- 
tion between  the  teeth  of  any  one  manufacturer.  The  end  of  all  this 
is  a  chaos  of  confusion  doubly  confounded,  a  vast  heterogeneous  mass 
of  artificial  teeth  in  which  no  real  artistic  principle  has  been  em- 
bodied. The  present  method,  even  at  its  highest  and  best,  that  is  to 
say,  when  natural  teeth  are  copied  as  closely  as  possible,  is  an  artis- 
tic failure,  because  a  work  of  art  cannot  be  produced  by  baldly  copy- 
ing ISTature. 

Let  me  repeat  here  and  emphasize  what  I  have  said  in  a  former 
paper  on  this  subject,  that  while  all  art  work  must  be  founded  on  the 
most  intimate,  penetrating  and  thorough  study  of  Mature  that  it  may 
be  true  to  life,  yet  truth  to  life  means  much  more  than  an  indiscrimi- 


^In  the  so-called  Natural-form  teeth  on  the  market  I  have  noticed  that  certain  natural  defects 
have  been  copied  which  make  a  perfect  anatomical  occlusion  impossible. 

27 


J.  Leon  Williams,  D.D.S. 

nate  coiisideratiou  and  acceptauce  of  a  mere  welter  of  facts.  It 
means  the  appreciation  and  understanding  of  the  relative  value  of 
facts,  and  the  power  or  faculty  of  discriminating  between  what  is  of 
small  value  and  what  is  important,  characteristic,  relevant,  line,  all 
that  is  really  vital  to  the  subject.  And  that  statement  fairly  intro- 
duces the  whole  problem  in  the  constructive  part  of  our  work,  which 
we  now  approach.  The  heart  of  that  problem  is  such  a  thorough 
mastery  of  all  the  facts  of  Nature  as  will  enable  us  to  know  what  it 
is  that  gives  character  in  our  work  and  what  detracts  from  it;  what 
makes  it  beautiful  or  what  causes  it  to  look  ugly  or  commonplace. 

Out  of  the  vast  confusion  and  imperfection  of  Nature  we  have 
to  isolate,  so  far  as  we  can,  the  pure  elements  of  truth  and  beauty  in 
tooth  form,  and  impress  those  elements  into  our  service  in  the  work 
of  designing  a  system  of  artificial  teeth.  We  have  to  attempt  what 
every  artist  undertakes  when  he  seeks  to  give  expression  to  a  more 
or  less  ideal  conception  he  has  formed  after  long  study  and  com- 
munion with  ^Nature. 

'^  -^  *% 

When  that  little  group  of  French  artists  known  as  ''The  Bar- 
bizon  School"  were  living  together  on  the  borders  of  the  forest  of 
Fontainebleu,  someone  asked  Millais  one  day  which  tree  he  thought 
the  most  beautiful,  from  the  artistic  point  of  view.  After  a  few  mo- 
ments' consideration,  he  replied:  "The  one  that  is  in  harmony  with 
its  surroundings."  A  fundamental  principle  in  art  was  never  more 
finely  stated.  Exactly  the  same  language  may  be  used  to  express  the 
relationship  between  tooth  form  and  face.  That  tooth  is  most  beau- 
tiful for  any  face  which  is  in  most  perfect  harmony  with  it.  Very 
well,  then  we  have  to  determine,  if  we  can,  just  what  it  is  that  con- 
stitutes this  harmony.  Is  it  entirely  a  matter  of  taste  and  individual 
judgment,  or  is  there  a  principle  involved  which  may  be  demonstrated 
so  that  all  may  see  and  benefit  by  it  ? 

Here,  as  always,  we  must  go  to  ISTature,  not  to  copy  baldly  every- 
thing that  we  find,  but  to  discover  the  essential  thing.  Everyone 
who  has  had  any  experience  in  this  field  knows  that  if  he  were  to 
place  a  set  of  oval  teeth  in  the  mouth  of  a  person  who  had  a  very 
square  face,  or  a  set  of  long  teeth  in  a  very  short  face,  the  dishar- 
mony or  falseness  would  be  glaringly  evident.  Even  the  novice  in 
dentistry  would  almost  instinctively  select  a  square  tooth  for  a  square 
face,  and  a  short  tooth  for  a  short  face.  But  why  are  the  straight 
lines  of  a  square  tooth  in  harmony  with  a  square  face,  and  the  curved 
lines  of  an  oval  tooth  in  harmony  with  an  oval  face  ?     If  we  can  dem- 

28 


"A  IsTew  Classification  of  Tooth  Eoems" 

onstrate  the  application  of  a  principle  in  an  obvions  case,  then  we 
may  also  he  able  to  apply  it  when  the  conditions  are  somewhat  more 
complex  or  obscure.  I  can  hardly  repeat  too  frequently  that  the  whole 
problem  is  purely  an  art  problem,  because  that  very  important  fact 
has  never  been  sufficiently  recognized.  ISTow,  in  all  works  of  art, 
whether  of  drawing,  painting,  sculpture  or  architecture,  harmony  or 
balance  is  secured  in  two  ways,  or  by  the  application  of  two  rules — 
by  parallelism  and  by  opposition  of  line  and  curve,  and  usually  by 
the  combination  of  the  two.  Excluding  color  for  the  moment,  that 
is  the  most  fundamental  thing  in  all  art  work.  The  severe,  classic 
beauty  of  a  Greek  temple  is  secured  almost  wholly  by  the  parallel  lines 
of  the  columns,  which  are  not  quite  parallel  or  quite  straight.  And 
those  upward  shooting  lines  also  constitute  the  chief  element  of  beauty 
in  the  more  ornate  Gothic  cathedral  of  later  times.  The  beauty  of 
the  Apollo  Belvedere  or  the  Venus  de  Milo  is  entirely  founded  on 
the  balance  or  opposition  of  curved  lines,  and  a  painting  by  Turner 
or  Claude  or  any  other  great  master  owes  its  artistic  merits,  so  far 
as  composition  is  involved,  entirely  to  the  balance  of  both  straight 
and  curved  lines. 

-^  '^  -^ 

The  principal  laws  of  harmony  in  all  art  work  involving  out- 
line may  be  briefly  stated  as  follows:  Lines  that  are  parallel  or 
nearly  so  are  harmonious;  lines  that  converge  or  diverge  must  have 
other  lines,  shorter  or  less  in  number,  set  in  opposition  to  them  to 
produce  harmony.  Curved  lines  running  in  a  similar  direction  are 
harmonious,  but  branching  or  diverging  curved  lines  also  require 
opposition  lines  to  complete  their  harmony. 

Those  laws  or  rules  are  just  as  applicable  to  the  designing  and 
use  of  artificial  teeth  as  to  building  a  temple  or  carving  a  statue. 
They  are  the  only  rules  by  means  of  which  a  high  degree  of  success 
may  be  reached  in  the  adaptation  of  tooth  form  to  facial  contour,  and 
their  application  is  perfectly  simple  and  free  from  ambiguity,  as  we 
shall  see  presently. 

During  all  the  time  that  I  was  laying  before  you  proofs  of  the 
fallacy  of  the  theory  of  temperamental  tooth  form,  of  the  theory  of 
racial  tooth  forms,  of  the  idea  that  jSTature  always  produces  harmoni- 
ous tooth  forms,  and  the  notion  that  the  way  to  produce  a  system,  or 
rather,  the  absence  of  a  system,  in  the  making  of  artificial  teeth  is  to 
copy  natural  sets  of  teeth — while  I  was  presenting  all  of  those  proofs, 
I  was,  at  the  same  time,  by  use  of  the  facts  those  proofs  contain, 
building  up  a  system  of  classification  founded  not  on  imaginary  dis- 

29 


J.  Leon  Williaims,  D.D.S. 

tinctions  but  on  scientific  realities.  The  facts  that  disprove  the  tem- 
peramental theory  are  the  facts  on  which  the  new  classification  is 
based. 

We  are  now  in  a  position  to  gather  np  the  somewhat  scattered 
threads  of  our  proofs  and  arguments  and  to  show  their  true  signifi- 
cance in  the  real  work  of  desig-ning  a  new  system  of  artificial  teeth. 
As  a  solid  basis  for  that,  we  have  established  a  new  classification  for 
natural  teeth  in  the  three  primitive  forms  shown  and  the  secondary 
and  other  forms  produced  by  the  crossing  of  these  primary  forms. 

In  those  three  primary  forms  of  teeth  we  have  all  the  elements  of 
design  necessary  for  producing  an  indefinite  number  of  varieties  of 
artificial  teeth.  But  an  indefinite  number  are  not  required.  On  the 
contrary,  we  require  comparatively  few  forms,  for  the  reason  that 
there  are  but  few  types  of  human  faces. 

Referring,  as  I  understood,  to  this  subject,  one  of  the  eminent 
gentlemen  who  discussed  the  paper  which  I  read  here  in  December, 
expressed  the  opinion  that  perhaps  the  last  word  in  artificial  teeth 
had  not  yet  been  said.  Well,  heaven  forfend  that  the  last  word  on 
any  subject  be  said  by  us.  That  would  leave  our  successors  in  the 
unenviable  position  of  having  nothing  to  say. 

•^  '^  '^ 

But  let  us  examine,  a  little,  that  expression  "the  last  word"  with 
reference  to  certain  phases  of  the  Trubyte  System  of  teeth.  What  is 
the  distinguishing  feature  of  this  new  system  ?  The  forms  of  the  teeth 
and  the  fundamental,  scientific  principles  on  which  they  have  been 
worked  out?  While  the  "last  word"  can  never  be  said  on  any  sub- 
ject, yet  you  have  all  heard  of  ultimate  facts  in  nature.  These  ulti- 
mate facts,  once  discovered,  remain  ultimate  facts  forever.  More  may 
be  learned  about  the  far  reaching  significance  of  these  facts,  but  noth- 
ing can  ever  be  learned  which  will  upset  them  or  in  any  way  change 
their  essential  meaning. 

The  law  of  gravitation  is  an  ultimate  fact  of  nature.  The  turn- 
ing of  the  earth  on  its  axis  is  another.  We  may  go  on  forever  learn- 
ing more  about  these  great  truths,  but  no  further  discovery  will  ever 
change  the  essential  fact.  ISTow  in  form  in  nature  there  are  certain 
ultimate  facts.  The  square  is  one,  the  equilateral  triangle  is  another 
and  the  circle  is  a  third.  You  can  never  get  anything  more  square 
than  an  area  bounded  by  four  equal  sides,  the  four  corners  of  which 
are  right  angles. 

You  can  never  get  anything  more  round  than  an  area  described 
by  a  line  every  point  of  which  is  equidistant  from  a  fixed  center.  These 

30 


"A  ITew  Classification  of  Tooth  Tokms" 

are  ultimate  facts.  So  this  discovery  which  I  have  made  of  three 
primary  forms  of  teeth  is  one  of  those  ultimate  facts  of  nature.  That 
form  of  central  incisor  which  approaches  most  closely  to  the  square 
must  always  stand  as  the  typal  tooth  in  that  class,  and  that  form 
which  has  the  straightest  and  most  converging  lines  and  a  section  of 
which  consequently  most  closely  approximates  an  equilateral  triangle 
must,  necessarily,  always  stand  as  the  typal  form  in  Class  II.  Like- 
wise that  tooth  in  Class  III,  which  embodies  most  of  the  elements  of 
the  circle  will  always  be  the  representative  typal  tooth  in  that  class. 
I  submit  that  there  is  no  getting  away  from  the  logic  of  that  proposition. 


Illustration  No.  19 
The  three  simple  forms  from  which  all  other  forms  are  made 


If  anyone  can  find  a  squarer  tooth  or  a  more  pyramidal-shaped 
tooth  or  a  tooth  with  more  marked  curves  in  its  proximal  lines  than 
those  I  have  exhibited  as  specimens  of  the  three  classes,  he  will  not 
injure  my  discovery  or  the  classification  founded  on  it.  On  the  con- 
trary, he  will  further  confirm  and  make  it  more  positive.  So  far, 
then,  as  the  classification  of  human  teeth  is  concerned,  this  is  the  last 
word  in  the  sense  that  it  is  a  statement  of  ultimate  facts,  and  the 
designing  of  artificial  teeth  for  all  future  time  must  be  based  on  those 
ultimate  facts.  When  the  mind  has  once  grasped  an  essential  truth 
it  can  never  let  go  of  it.  Other  manufacturers  may  bring  out  teeth 
shaped  like  those  in  the  Trubyte  System  without  attempting  to  classify 
them,  but  just  to  the  extent  that  they  are  not  classified  they  will  be 

31 


J.  Leon  Williams,  D.D.S. 

inconvenient  for  the  dealer  to  handle  and  the  dentist  to  select  and 
order.  To  produce  artificial  teeth  on  any  other  than  the  three-form 
basis  is  to  present  the  play  of  Hamlet  with  Hamlet  left  out. 

'^  '^  '^ 

In  the  elements  of  design  we  have  in  the  three  primary  types  of 
natural  teeth,  we  see  what  a  perfect  means  we  have  for  producing 
artificial  teeth  of  all  forms  necessary  for  the  most  complete  harmonious 
relations  with  every  type  of  human  face.  When  we  come  to  analyze 
these  elements  of  design,  we  find  that  they  are  very  simple,  but,  as  I 
have  said,  capable  of  an  indefinite  number  of  beautiful  combinations. 


Illustration  No.  20 
Elements  of  design,  separated 

You  have  on  the  screen  a  picture  of  these  elements  of  design, 
separated  or  analyzed  as  a  few  curved  and  straight  lines,  and  combined 
as  one  of  the  typical  forms  of  our  classification.  Let  us  see  how  by 
slight  variations  of  those  few  lines  we  can  produce  every  conceivable 
form  of  human  tooth — and  you  will  see  that  we  produce  our  varia- 
tions after  the  method  of  JSTature — by  crossing  the  typical  forms. 

I  told  you  in  a  former  paper  that  all  the  fundamental  principles 
of  art  and  design  could  be  applied  to  the  making  of  artificial  teeth. 
Now  what  does  a  competent  artist  do  when  he  has  it  in  mind  to  design 
a  fine  picture?  He  decides  on  the  subject  and  general  plan  of  his 
painting,  and  then  proceeds  to  make  many  careful  studies  of  all  the 
elements  which  are  to  appear  in  the  finished  work.  When  it  comes  to 
the  final  composition  of  the  picture,  he  probably  makes  several  trials 
before  he  gets  that  perfect  balance  of  line  and  mass  that  satisfies  him. 

32 


"A  l^Ew  Classification  of  Tooth  Foems" 


That  is  precisely  the  method  that  has  been  employed  in  designing 
all  these  forms  of  teeth.  The  suggestions  for  most  of  the  designs  have 
come  from  natural  teeth.  The  first  step  has  always  been  to  make  a 
number  of  accurate  studies  or  drawings  of  the  outlines  of  those  nat- 
ural teeth  most  closely  resembling  the  intended  form.  First  the  cen- 
trals, then  the  laterals  and  canines,  and  last,  the  lower  incisors  are 
all  laid  out  so  that  all  can  be  seen  at  once  and  compared.  There  will 
be  some  lines  that  balance,  that  are  harmonious,  and  others  that  are 
discordant.     The  problem  is  precisely  that  of  designing  a  good  com- 


Illustration  No.  21 
Elements  of  design,  partly  assembled 

position — to  secure  perfect  harmony  of  line  and  mass,  and  that  is  not 
an  easy  matter  in  so  small  an  object  as  a  tooth.  When  it  comes  to  the 
carving,  several  are  sometimes  discarded  before  the  satisfactory  result 
is  reached. 

'^  '^  '^ 

All  variations  in  the  models  of  artificial  teeth  designed  for  the 
different  types  of  face  are  produced  by  slightly  varying  the  curvature 
and  balance  of  line  of  those  few  simple  elements  of  design  in  accord- 
ance with  the  contour  of  face  for  which  the  tooth  is  designed.  But 
the  knowledge  of  how  to  do  that  in  the  best  and  most  artistic  manner 
possible  can  only  be  acquired,  as  all  other  artistic  knowledge  is,  by 
much  experiment  and  by  long  and  concentrated  study  of  human  teeth 
and  human  faces. 

33 


J.  Leon  Williams,  D.D.S. 

The  aim,  in  designing  artificial  teeth,  should  always  be  to  main- 
tain character  in  the  tooth  by  keeping  its  typal  or  class  features  dom- 
inant. The  most  uninteresting  and  unattractive  tooth  is  one  in  which 
the  characteristics  of  all  three  of  the  primary  types  have  become  so 
blended  that  it  has  no  distinction.  It  is  characterless.  This  whole 
subject  can  be  illustrated  and  demonstrated  in  a  few  moments  by  dia- 
grams or  outline  drawings. 

Illustration  No.  22  shows  perfectly  accurate  outline  drawings 
of  specimens  of  natural  teeth  of  the  three  primary  classes.  You  will 
remember  that  when  I  was  showing  the  teeth  of  the  orang-outang  I 
called  your  attention  to  the  great  variation  in  the  proportion  of  width 
to  length  shown  in  the  teeth  in  Class  I.  The  lower  row  in  the  view 
on  the  screen  illustrates  this  point  again,  and  I  will  ask  you  to  keep  it 
in  mind  when  I  come  to  describe  the  system  of  constructing  porcelain 
teeth. 


Illustration  No.  22.     Variations  in  three  primary  types 


The  teeth  in  the  other  two  rows  have  all  been  drawn  to  the  same 
length,  but  the  proportional  width  has  been  preserved.  By  the  cross- 
ing of  these  three  types,  N^ature  has  produced  every  form  of  human 
tooth  that  has  existed,  through  all  the  ages  down  to  the  present  time. 
In  the  very  nature  of  things,  some  one  of  those  forms  or  variations  will 
be  better  adapted  to  or  more  harmonious  with  a  given  type  of  face 
than  another.  But  we  have  seen  that  iSTature  exercises  no  very  fine 
discrimination  in  adapting  tooth  form  to  facial  contour.  That  means 
that  the  vast  majority  of  her  variations  in  teeth  are  of  no  particular 
artistic  value.     They  can  be  discarded  or  ignored  so  far  as  a  system 

34 


"A  Nnw  Classification  of  Tooth  Forms" 


Illustration  No.  23 
Typal   forms   numbered.     Modifications   of  those   forms  by  blendings   shown  beside   typal   forms. 


E     nr. 


lo     M.  nn,  w: 


A< 


A 


(D. 


Illustration  No.  24 


35 


J.  Leon  Williams,  D.D.S. 

of  teeth  for  edentulous  cases  is  concerned,  and  the  forms  that  are  pro- 
duced can  be  far  more  perfectly  adapted  to  characteristic  facial  outline 
than  any  except  the  few  rare  triumphs  of  Nature. 

'^  '^  '^ 

The  facts  that  I  am  most  desirous  of  getting  clearly  before  you 
are  that  this  system  is  a  perfectly  natural  one,  and  that  all  the  meth- 
ods by  means  of  which  it  has  been  worked  out  are  no  other  than  such 
modifications  of  N^ature's  own  methods  of  working  as  will  lead  us 
more  directly  and  quickly  to  our  desired  end,  and  in  that  end  give  us 
more  uniformly  perfect  results  than  are  ever  found  in  Nature.  In 
methods  and  in  results  it  is  a  perfected  artistic  compendium  of  all  of 
Nature's  work  in  teeth. 

Our  position  in  this  matter  of  design,  in  relation  to  one  who  pro- 
duces artificial  teeth  by  simply  copying  natural  ones,  may  very  justly 
be  likened  to  that  of  the  breeder  of  animals  or  the  producer  of  new 
and  improved  forms  of  fruit.  We  are  no  longer  blind  followers  of 
Nature,  imitating  her  defects,  but  intelligent  selectors  of  principles 
and  utilizers  of  her  secret  processes.  We  eliminate  defects.  We  se- 
cure harmony.  The  finished  results  are,  in  very  truth,  more  natural 
than  any  set  of  natural  teeth  because  harmony  is  the  very  first  essential 
of  naturalness.  We  become  the  master  of  Nature  instead  of  being  her 
servant.  We  utilize  everything  that  is  vital  and  significant  and  elim- 
inate all  that  detracts  from  perfection.  Our  one  aim  in  all  our  work 
is  the  establishment  of  harmony  between  outline  or  form  of  tooth  and 
outline  of  face.  And  we  achieve  that  by  the  proper  balance  and  curve 
of  line  in  the  tooth,  in  relation  to  the  type  of  face  for  which  it  is 
designed. 

If  I  state  the  problem  in  another  way  you  will  see  at  once  that  it 
is  so.  If  the  size  and  contour  of  a  tooth  is  exactly  right  for  a  given 
face,  then  the  harmony  is  perfect.  But  the  "contour"  of  a  tooth  is 
only  another  name  for  the  balance  of  line  and  curve  in  the  tooth.  If 
the  lines  and  curves  of  the  tooth  balance  or  are  in  harmony  with  the 
lines  and  curves  of  the  face,  then  the  highest  degree  of  perfection  at- 
tainable has  been  reached.  And  we  shall  see  that  there  is  no  difficulty 
in  achieving  that  perfect  result  in  all  edentulous  cases.  Let  us,  then, 
now  take  up  the  consideration  of  the  relations  of  typal  tooth  forms  to 

36 


"A  ]^EW  Classification  of  Tooth  Forms" 

facial  contours.  And  in  order  to  make  the  application  of  our  new 
principle  perfectly  plain,  we  will  begin  witli  the  outline  diagrams  of  the 
four  chief  types  of  faces.     (Illustration  ISTo.  25.) 

These  outline  diagrams  show  only  the  strong  main  lines  of  the 
faces,  and  thus  we  shall  be  able  to  see  quickly  and  clearly  the  relation 
of  tooth  form  to  these  lines. 

'^  ««fe  ««fe 

All  of  the  best  writers  that  I  know  on  the  subject  of  physiognomy 
are  agreed  that  there  are  but  three  well  marked  classes  or  types  of 
human  faces — the  square,  the  oval  and  the  tapering.  But  I  think  one 
strong  type  of  face  has  been  overlooked  by  all  writers  on  the  subject. 
It  is  the  form  which  shows  a  greater  width  below  the  eyes  than  above. 
The  whole  lower  part  of  the  face  is  round  and  rather  heavy,  and  the 
forehead  is  usually  dome-shaped.  I  call  this  the  ovoid  face  because 
it  resembles  the  form  of  skull  to  which  that  name  has  been  given.  ISTo 
form  of  tooth  has  ever  been  made  that  is  well  adapted  to  this  shape 
of  face,  but  those  of  Class  III  in  our  system  are  perfectly  suited  to  it. 
These  four  types  of  faces  have  several  modifications  which  we  shall 
consider  as  we  proceed. 

In  the  square  face  and  in  its  principal  modifications,  that  is  to 
say,  in  all  faces  the  sides  of  which  are  parallel  or  nearly  so,  we  secure 
perfect  harmony  with  the  teeth  of  Class  I. 

If  the  face  is  typical  or  severe  in  its  squareness,  then  we  must  use 
teeth  the  central  incisors  of  which  are  parallel  on  their  proximal  sides. 
But  the  great  majority  of  square  faces  is  not  of  this  type.  Usually 
there  is  a  slight  converging  of  the  lines  from  the  forehead  to  the  chin, 
and  the  teeth  should  therefore  have  lines  which  converge  slightly  toward 
the  neck.* 

The  oval  face  is  the  result  of  a  slight  rounding  of  the  angles  of 
the  square  face.  Exactly  the  same  modification  of  the  square  tooth 
produces  the  oval  tooth. 

Again,  in  the  ovoid  face,  our  tooth  outline  follows  the  general 
contour  of  the  face.    The  characteristic  of  this  type  of  face,  you  will 


*Iia  all  that  we  have  to  say  abotit  tooth  form,  it  is  always  to  be  understood  that  we  are 
speaking  of  the  upper  central  incisors.  It  is  these  teeth  that  are  the  chief  factor  in  deter- 
mining  harmony  with  the   face,  and  they  also  govern  the  type   of  all   other   teeth  in  the  set. 

37 


J.  Leox  WrLUAits,  D.D.S. 


Tapering  face. 


Ovoid   face. 


IDasbation  No.  25 


38 


'■'A  Xe-^  Classiticatiox  of  Tooth  Fokms" 

remember,  is  the  width.,  ro-andiiess  and  heaviness  of  the  lower  part. 
This  is  the  special  feature  of  the  teeth  in  Class  lU.  The  general 
character  of  the  tooth  of  this  class  and  the  flow  of  all  its  lines  corre- 
spond perfectly  with  the  ovoid  face.  In  all  of  the  foregoing  illustra- 
tdons  harmony  is  secured  by  parallelism  of  tooth  outline  and  face  out- 
line. 


Illustration  No.  26.     The  six  upper  an:eriors  in  the  three  primary  forms 


The  tapering  face  has  a  wider  range  of  variation  than  any  of  the 
other  types.  It  begins  as  a  slight  departure  from  the  square  face  by 
the  convergence  of  the  cheek  lines  toward  the  chin  and  it  presents 
every  gradation  of  change  from  this  to  the  extreme  convergence  seen 
in  the  very  pointed  chin. 

In  all  faces  of  this  character  the  lines  of  the  proximal  surfaces  of 
the  upper  central  incisors  run  in  opposition  to  the  lines  of  the  face. 
If  the  lines  of  the  face  converge  but  little  toward  the  chin  the  proxi- 
mal lines  of  the  teeth  should  converge  but  little  toward  the  neck  of  the 
tooth. 

The  amount  of  line  convergence  in  the  face  governs  the  amount 
in  the  teeth.  If  this  line  convergence  is  accompanied  by  rather  full, 
round  cheeks,  then  the  disto-proximal  surface  of  the  upper  centrals 
should  also  be  rounded  or  convex.     In  selecting  teeth  for  the  tapering 

face  of  any  degTee,  you  have  only  one  principle  to  keep  in  mind,  so 
far  as  tooth  form  is  concerned,  and  that  is  tliat  the  contour  lines  of 
yotir  upper  incisors  must  be,  in  a  general  way,  the  reverse  of  what 

39 


J.  Leon  Williams,  D.D.S. 

they  are  in  the  face.     The  obsen-ance  of  this  rule  will  always  give  vou 
perfect  harmony — the  harmony  of  opposition  of  line. 

If  I  have  now  made  clear  the  fundamental  governing  principle 
in  the  relation  of  facial  contour  to  tooth  form,  we  will  rapidly  pass  in 
review  a  few  photographs  of  the  more  striking  and  distinctive  types 
of  faces.     (Specimens  were  shown  on  the  screen.) 

'^  '^  '^ 

We  will  first  examine  the  forms  of  teeth  best  suited  to  the  square 
face  and  its  immediate  modifications,  the  shorter  and  longer  face  of 
the  same  type.  I  am  taking  these  all  together  in  three  groups  for  a 
special  reason.  When  we  were  looking  at  the  teeth  of  the  orang- 
outang you  will  remember  I  told  you  that  teeth  of  the  square  type, 
or  those  with  parallel  sides,  varied  more  in  proportion  of  width  to 
length  than  any  others,  and  I  added  that  as  the  same  fact  was  observ- 
able in  faces  I  had  designed  a  special  series  of  teeth  to  meet  these 
conditions.  This  series  is  known  as  Forms  1,  2,  3,  4  and  5  in  Class  I  as 
now  shown  on  the  screen  (Illustration  Xo.  27).  As  all  of  the  faces  are 
of  the  same  general  type,  differing  only  in  proportion  of  width  to  length, 
so  the  teeth  are  of  one  type  differing  only  as  the  faces  do.  The  teeth  are 
not  of  the  most  severe  typal  form.  There  is  a  very  slight  convergence  of 
the  proximal  lines  and  a  slight  convexity  of  the  disto-proximal  surface. 
The  reason  for  that  is  that  there  are  but  very  few  faces  of  the  most 
severe,  square,  tvpal  form  and  even  for  these  the  forms  of  teeth  shown 
would  be  perfectly  suitable.  But  there  is  a  very  great  nimiber  and  a 
wide  range  of  faces  showing  slight  modification  of  the  square  type. 
It  is  to  meet  that  wide  range  of  face  found  in  nearlv  all  countries 
that  this  series  of  teeth  has  been  designed.  There  are  five  sizes  to  each 
form,  except  Form  4,  in  which  the  extremely  large  form  is  unnecessary. 
I  will  ask  your  close  attention  for  a  few  moments  while  I  point  out  to 
you  what  it  means  to  have  a  series  of  teeth  of  one  model  like  this.  In  the 
first  place,  there  is  a  very  wide  range  of  face  in  the  long,  medium  and 
short  varieties  of  the  square  type  for  which  this  series  is  perfectly  suited. 
But  its  usefulness  and  convenience  extends  much  beyond  that.  You 
have  all  had  the  experience  of  finding  the  exact  t}^e  of  tooth  you 
wanted  for  a  given  case,  but  in  a  larger  or  smaller  size  than  the  case 
demanded,  and  you  know  the  feeling  it  has  given  you  to  find  that 'the 
model  tooth  you  wanted  was  not  made  in  any  other  size  than  the  one 
you  could  not  use.  Well,  that  situation  can  never  occur  in  the  system 
of  teeth  now  suggested.  JSTo  form  will  ever  be  brought  out  in  one 
size  only.  That  seems  to  me  to  be  about  the  most  senseless  feature 
that  can  be  charged  to  the  old  regime. 

40 


"A  jSTew  Classification  of  Tooth  Foems" 
CLASS   I   MOULDS 

(Illustrations    show    form   but    not    sizes.) 


Form    1.      The    long    modification    of    the    square    form. 
Sizes   from   small   to   large   from   moulds    IC,    ID,    IE,    IF,    IH. 


Form    2.      The    medium    long    modification    of    the    square    form. 
Sizes  from  small  to  large  from  moulds  2C,  2D,  2E,  2F,  2H. 


Form  3.     The  short  modification   of  the  square   form. 
Sizes    from    small    to    large    from    moulds    3C,    3D,    3E,    3F,    3H. 


Form    4.      The   feminine    modification. 
Sizes  from  small  to  large  from  moulds  4C,  4D,  4E,  4F. 


Form    S.      Oval    modification. 
Sizes  from  small  to  large  from  moulds  5C,  5D,  5E,  SF,  5H. 

Illustration  No.   27 

41 


J.  Leojst  Williams,  D.D.S. 


Square   face — long. 
Class  I,  Form   1. 


Square   face — long. 
Class  I,  Form   1. 


Square  face — medium. 
Class    I,    Form    2. 


Feminine   square. 
Class    I,    Form    4. 


Square    face — short. 
Class  I,   Form   3. 


Oval   face,   a   modification   of  the   square. 
Class  I,  Form  5. 


Illustration  No.  28 


42 


"A  JSTew  CLAssiFiCATioisr  OF  Tooth  Foems" 

In  this  particular  series  we  have  five  sizes  in  each  group,  except 
Form  4,  which  has  four  sizes.  But  there  is  more  than  that  in  it.  In  all 
cases  for  partial  plates  the  absorption  following  extraction  makes  it 
necessary  to  use  a  tooth  longer  than  the  adjoining  natural  one,  yet  you 
should  have  a  tooth  of  the  same  general  type.  Suppose  it  is  a  case  in 
which  one  central  of  the  short  series,  iSTo.  3,  is  missing.  The  space  to 
be  filled  demanding  a  longer  tooth  of  this  type,  you  simply  pass  from 
Form  3  to  Form  2  and  find  exactly  what  you  require.  If  your  standing 
natural  central  should  be  of  medium  length  then  you  pass  from  2  to  1  to 
get  what  you  want.  !N'ow,  if  you  will  think  for  a  moment  what  it  means 
to  have  such  a  range  of  selection  in  a  form  of  tooth  for  a  great  variety 
of  the  type  of  face  most  frequently  met,  you  will,  I  think,  see  that 
this  one  series  of  24  sets  is  far  more  valuable  for  a  dentist  to 
keep  in  stock  than  twenty  times  that  number  of  the  heterogeneous 
moulds  without  system  or  relation  as  formerly  made,  not  to  mention 
any  of  the  other  very  important  points  of  superiority  of  the  new  models. 

The  short  tooth  of  Form  3  is,  of  course,  for  the  type  of  short  face, 
shown  in  Illustration  ISTo.  28.  Form  2  is  for  faces  of  medium  length, 
and  Form  1  is  for  the  long  faces. 

The  arch  of  the  teeth  in  the  upper  jaw  of  the  short  and  medium 
square  faces  is  the  segment  of  a  larger  circle  than  would  be  required 
for  any  other  type  of  face.  There  is  but  little  overlap  of  the  upper 
incisors  in  this  type  of  face  and  when  the  teeth  become  worn  the  bite 
is  nearly  square,  especially  in  the  short  face.  In  the  long  face  there  is 
usually  some  overlapping  of  the  centrals  or  laterals. 

-^fe  '^  «% 

Illustration  'No.  28  shows  the  first  modification  of  the  square  face 
in  the  direction  of  the  oval.  It  is,  perhaps,  more  frequently  met  with  in 
the  United  States  than  in  any  other  form.  Teeth  of  Form  2,  Class  I, 
are  also  perfectly  suited  for  the  male  face  of  this  type,  but  for  the 
feminine  face  I  have  designed  and  carved  Form  4,  Class  I.  The 
greatest  possible  care  was  given  to  the  modelling  of  this  group  of  teeth 
and  they  have  been  designed  to  produce  a  perfect  harmony  with  one 
of  the  finest  types  of  the  feminine  face  in  America  and  England.  Slight 
overlapping  of  laterals  adds  to  the  beauty  and  naturalness  of  appear- 
ance. The  general  appearance  of  the  arch  is  the  same  as  in  the  square 
face,  but  is  a  little  more  rounded  at  the  front.  They  have  a  slight  round- 
ing of  the  mesial  and  distal  incisal  angles.  Slight  overlapping  of  the 
centrals  is  nearly  always  found  in  the  finest  specimens  of  natural  teeth 
of  this  type. 

In  the  tapering  form  of  face  the  female  type  is  the  most  deli- 
cate,   and  by  many   considered  the  most   artistic   form   of   feminine 

43 


J.  Leon  Williams,  D.D.S. 


beauty.  It  is  a  type  of  face  frequently  found  in  Italy.  Women  with 
faces  of  this  type  were  usually  selected  by  the  great  Italian  masters 
as  models  for  their  representations  of  the  Madonna,  and  it  is  worthy 
of  note  that  this  is  the  type  of  face  depicted  by  the  great  English  por- 
trait painters  of  the  late  eighteenth  century  as  that  of  the  famous 
beauty,  Emma,  Lady  Hamilton,  All  of  the  teeth  in  Class  II,  except 
Form  1,  have  been  designed  for  this  form  of  face.  The  masculine 
face  of  this  type,  with  converging  lines,  often  presents  very  strong 


Tapering   face — long. 
Class   II,    Form    1. 


Tapering    face. 
Class   II,    Form 


Tapering   face — long. 
Class   II,   Form   3. 


Illustration  No.  29 


Tapering   face. 
Class   II,    Form  4. 


features.  The  lines  of  the  cheek,  from  the  malar  bones  to  the  lower 
jaw,  although  couA'-erging  considerably  towards  the  chin,  are  very 
straight  and  firm.  For  this  type  of  face  the  teeth  of  Form  1,  Class  II, 
have  been  made.  There  is  no  overlapping  of  the  teeth  in  the  strong- 
est type  of  face  of  this  class. 


44 


"A  ;N'ew  Ci^ssification  of  Tooth  Foems" 

For  tlie  shorter  tapering  female  faces  in  this  class  forms  have 
been  designed,  and  also  for  the  medium  and  longer  tapering  faces. 
In  all  of  these  types,  particularly  those  with  the  sharper  form  of  face, 
with  a  somewhat  pointed  arch,  there  is  often  more  or  less  overlapping 
of  both  centrals  and  laterals,  but  especially  centrals. 

On  page  44  are  two  of  the  long  tapering  faces  which  are,  I  be- 
lieve, much  more  frequently  found  in  England  and  some  parts  of  Italy 
than  in  Germany  or  the  United  States,  although  many  of  the  old  iSTew 
England  stock  had  long  faces.  The  teeth  best  suited  to  this  type  of 
face  will  be  rather  long,  with  converging  proximal  lines  such  as  are 
seen  in  forms  of  Class  XL  We  sometimes  find  in  faces  of  this  type, 
in  England,  a  rather  short  upper  lip.  In  such  cases,  and,  in  fact,  in 
all  cases  where  we  find  a  short  upper  lip  combined  with  prominence 
of  jaw,  I  think  it  better  always  to  use  short  teeth  or  those  of  medium 
length. 

But  teeth  with  tapering  proximal  sides  should  be  selected  for  all 
variations  of  the  tapering  face.  The  duplication  and  reversal  of  the 
lines  of  the  face  in  the  shorter  lines  of  the  teeth  produces  an  effect  of 
balance  and  harmony  which  a  trained  artist  would  perceive  and  under- 
stand in  a  moment.  If  the  face  is  long  and  only  slightly  tapering, 
then  the  teeth  of  Form  1,  Class  I  wiU  give  a  good  effect.  In  all  taper- 
ing faces  with  rather  full  cheeks  the  teeth  in  Class  III  are  also  per- 
fectly suitable.  Harmony  is  produced  with  these  teeth,  as  with  those 
of  Class  II,  by  contrast  or  reversal  of  line. 


<%  'fgf  -^ 

Illustration  ]^o.  30  is  the  type  of  face  to  which  I  have  given  the 
name  "ovoid,"  and  for  which  the  teeth  in  Class  III  have  been  specially 
made.  The  greatest  width  of  the  face,  as  I  have  already  pointed  out,  is 
in  the  region  of  the  malar  bones.  But  the  entire  lower  part  of  the  face 
is  heavier  than  in  any  other  type.  The  cheeks  are  full,  round,  and  thick. 
Women  with  these  facial  characteristics  are  sometimes  spoken  of  as 
belonging  to  the  voluptuous  type.  The  beautifully  curved  outlines  and 
generally  rounded  character  of  the  teeth  in  Class  III  will  give  the 
most  harmonious  and  satisfactory  effects  in  faces  of  this  t}^e. 

45 


J.  Leon  Williams,  D.D.S. 

Slight  depression  of  the  laterals  gives  that  proiniiieiice  to  the 
canines  which  is  in  keeping  with  the  strongest  form  of  this  face.  With 
the  more  delicate  and  refined  type  of  face  of  this  class  there  should  be 
overlapping  of  the  laterals.  The  arch,  as  you  see,  is  rounder  than  in 
any  other  type. 


Ovoid  face. 
Class  III,   Form   1 


Ovoid  face. 
Class  III,   Form  2 


Ovoid   face. 
Class  III,   Form  3 


Illustration  No.  30 


Ovoid  Face. 
Class  III,   Form  4 


I  have  shown  you  how  the  bolder  forms  of  teeth  in  the  present 
system  are  adapted  to  the  typal  forms  of  faces.  The  general  appli- 
cation of  the  system  to  modifications  of  the  typal  faces  can  best  be 


46 


"A  !N"ew  Classification  or  Tooth  Forms'^ 
CLASS   II  MOULDS 

(Illustrations   show    form   but   not   sizes.) 


Form  1.     Class  II. 
A  severe,  nearly  typal  form. 

Sizes  from  small  to  large  from  moulds  IL,   IM,  IN,  IP,  IR. 


Form  2.     Class  II. 
Slightly  modified  by   crossing   with    Class   III. 

Sizes  from  small  to  large  from  moulds  2L,  2M,  2N,  2P,   2IL 


Form   3.      Class   II. 
Slightly  modified  by  crossing  with  Class  I. 

Sizes  from  small  to  large  from  moulds  3L,   3M,  3N,  3P,   3R. 


Form  4.     Class  II. 
Modified  by  Class  III,   a  little  more  than  Form  2. 

Sizes  from  small  to  large   from  moulds  4L,   4M,   4N,  4P,   4R. 

Illustration  No.  31 

47 


J.  Leon  Williams,  D.D.S. 


seen  bj  exhibiting  the  table  of  dassilication,  (pages  49  to  61),  in  which 
will  appear  the  whole  system  in  one  view. 

This  table  of  classification  presents  three  classes  founded  on  the 
three  primitive  types  of  natural  teeth.  Each  class  contains  modifications 
of  the  primary  types  corresponding  with  the  variations  in  the  types  of 
faces.  The  forms  most  closely  resembling  the  primitive  forms  in 
natural  teeth,  are  most  suitable  for  the  strong,  characteristic  or  typal 
forms  of  faces.  In  nearly  all  faces  which  result  from  the  crossing  of 
types  we  shall  find  one  or  other  type  dominant.  Any  given  face  will 
approximate  to  the  square,  the  oval,  the  tapering  or  the  ovoid  form. 
We  shall  therefore  determine  the  dominant  factor  and  select  our  teeth 
accordingly.  Each  section  of  the  table  represents  a  series  of  sizes 
of  one  form  of  tooth.  The  teeth  in  any  one  section  are  called  a 
series,  the  only  difference  in  all  the  teeth  in  a  series  being  that  of 
size.  They  are  all  precisely  the  same  form,  but  in  sizes  to  match  vari- 
ations in  size  of  faces  of  the  same  type.  This  is  an  entirely  new  fea- 
ture in  the  manufacture  of  artificial  teeth.  How  often  we  have  had 
the  experience  of  fixing  upon  a  certain  shape  of  tooth,  but  which  was 
either  too  large  or  too  small  for  our  purpose,  only  to  find  that  no  other 
size  of  that  model  was  made.  That,  to  my  mind,  has  always  been  one 
of  the  most  incomprehensible  inconsistencies  of  the  old  order  of  things. 
Three  or  four  sizes  in  each  series  will  meet  nine-tenths  of  the  demands. 
While  on  this  subject  of  size  of  teeth  perhaps  I  had  better  say  that  I 
think  the  chief  determining  factor  in  adapting  size  of  teeth  to  face 
should  be  size  of  external  mouth,  opening  and  other  features  rather 
than  general  size  of  face.  Small  teeth  in  a  mouth  with  large  opening, 
no  matter  what  the  size  of  face  may  be,  will  always  look  hideous. 

You  are  beginning  to  see  now  the  comprehensiveness,  the  complete- 
ness and  the  simplicity  of  this  scheme  of  classification.  In  this  series 
of  tables  you  have  an  arrangement  that  banishes  all  uncertainty  and 
guesswork.  A  patient  comes  to  you  for  artificial  teeth.  You  first  de- 
termine in  what  class  the  face  belongs.  If  it  is  not  a  pure  type  you 
decide  on  the  dominant  feature  and  determine  that  it  is  a  modifica- 
tion of  the  square,  the  oval,  or  the  tapering  face.  You  then  select  your 
teeth  on  precisely  the  same  principle.     If  it  is  a  square  face  just  pass- 

( Continued  on  page  62.) 

48 


Classification  Table 
Trubyte  Teeth 


CLASS  I 
MODIFICATIONS  OF  THE  SQUARE  TYPE 

FIVE  FORMS  IN  GRADED  SIZES 


WHEN  DIMENSIONS  ARE  NOT  GIVEN  THE  SIZES  ARE  IN  PREPARATION. 
AI,!^  DIMENSIONS  ARE  IN  MILUMETERS. 

Similar  dimensions  in  plain  vulcanite  pin  teeth;   combination  sets  with  individual  diatoric 
posteriors,  and  combination  sets  with  molar  blocks. 

FORM  1.    The  Long  Modification  of  the  Square  Type. 

Illustration  represents  form  but  not  sizes. 


Form    1.      The    long    modification    of   the    square    form. 
Sizes   from  small   to   large   from  moulds   IC,    ID,    IE,   IF,    IH. 


UPPERS 

Mould 
No. 

I^ength 

Central 

Without  Collar 

Width 

6  anteriors 

Set  up 

Width 
Full   14 
Setup 

Combined 

Bite  and  Shut 

of  Central 

Width  of 
Central 

IC 
ID 
IE 
IF 
IH 

9.75 
10.25 
10.75 
11.50 

42-43 
45. 
46-47 
51. 

103. 
108. 
109-110 
123-124 

8. 

9. 

9.5 

9.5 

7. 
7.5 
8. 
8.5 

LOWERS 


Mould 
No. 

I,ength 

Central 

Without  Collar 

width 

6  anteriors 

Setup 

width 
Full    14 
Set  up 

Combined 

Bite  and  Shut 

of  Central 

Width 

Four 

Incisors 

IC 

id 

9. 

32.5 

102. 

9. 

21. 

IE 

9. 

36. 

104. 

9. 

22.5 

IF 

9.5 

36. 

106. 

9. 

23. 

IH 

10.25 

40. 

115. 

9.5 

25. 

49 


J.  Leon  Williams,  D.D.S. 


CLASS  I. 
FORM  2 — Medium  Long,  Souare. 


Illustration  represents  form  but  not  sizes. 


Form  2.    The  medium  long  modification  of  the  square  form. 
Sizes  from  small  to  large  from  moulds  2C,  2D,  2E,  2F,  2H. 


UPPERS 


Mould 

Length 

Width 

Width 

Combined 

width  of 

No 

Central 

6  anteriors 

Full  14 

Bite  and  Shut 

Central 

Without  Collar 

Set  up 

Setup 

of  Central 

2  C 

8.50 

42-43 

102-103 

8. 

7. 

2  D 

9.25 

44 

103 

8.5 

7.5 

2  B 

10. 

46-47 

108-109 

9.25 

8. 

2  F 

10.75 

48-49 

110-111 

9.5 

8.25 

2  H 

LOWERS 


Mould 
No. 

Length 

Width 

Width 

Combined 

Width 

Central 

6  anteriors 

Full  14 

Bite  and  Shut 

Four 

Without  Collar 

Setup 

Set  up 

of  Central 

Incisors 

2  C 

8.5 

33. 

100 

7.5 

20. 

2  D 

9. 

34. 

101 

9. 

21.5 

2  n 

9. 

36.5 

106 

9. 

23. 

2  P 

10. 

37. 

106 

9.5 

23.5 

2  H 

50 


"A  N"ew  Classification  of  Tooth  Forms" 


CI.ASS  I. 
FORM  3— Short  Square. 


Illustration  represents  form  but  not  sizes. 


Form  3.     The  short  modification  of  the  square  form. 
Sizes   from    small   to   large    from   moulds    3C,    3D,    3E,    3F,    311. 


UPPERS 


Mould 
No. 

I^ength 

Central 

Without  Collar 

Width 

6  anteriors 

Setup 

Width 
Full  14 
Setup 

Combined 

Bite  and  Shut 

of  Central 

width  of 
Central 

3  C 
3  D 

3  K 

8. 
8.75 

44-45 
45-46 

105-106 
108-109 

8. 

8. 

7.75 
8. 

LOWERS 


Mould 
No. 

I^ength 

Central 

Without  Collar 

Width 

6  anteriors 

Setup 

Width 
Full  14 
Setup 

Combined 

Bite  and  Shut 

of  Central 

Width 

Four 

Incisors 

3  C 
3  D 
3  E 

7.75 
8.75 

35. 
36. 

103. 
106. 

8. 
8.50 

23. 

23. 

51 


J.  Leon  Williams,  D.D.S. 


CLASS  I. 
FORM  4 — The  Feminine  Modification  of  The  Square  Type. 


Illustration   represents   form   but  not  sizes. 


Form  4.     The  feminine  modification. 
Sizes  from  small  to  large  from  moulds  4C,   4D,   4E,   4F. 


UPPERS 


Mould 
No. 

Length 

Central 

Without  Collar 

Width 

6  anteriors 

Setup 

Width 
Full  14 
Setup 

Combined 

Bite  and  Shut 

of  Central 

Width  of 
Central 

4  C 
4  D 
4  E 
4  F 

9. 
10.0 

40. 
45. 

97. 

107. 

8. 
9. 

7. 
8. 

LOWERS 


Mould 
No. 

Ivcngth 

Central 

Without  Collar 

Width 

6  anteriors 

Set  up 

Width 
Full  14 
Set  up 

Combined 

Bite  and  Shut 

of  Central 

Width 

Four 

Incisors 

4  C 

4  D 

8. 

29. 

93. 

8. 

18. 

4  E 

4  F 

9. 

33. 

102-103 

8. 

21. 

52 


"A  'New  Classification^  of  Tooth  Foems" 


CLASS  I. 
FORM  5 — The  Oval  Modification  of  The  Square  Type. 


Illustration  represents  form  but  not  sizes. 


Form  5.     Oval  modification. 
Sizes  from  small  to  large  from  moulds  5C,  SD,  5E,  5F,  5H. 


UPPERS 


I^ength 

Width 

Width 

Combined 

Width  of 

Central 

6  anteriors 

Full  14 

Bite  and  Shut 

Without  Collar 

Setup 

Setup 

of  Central 

5  C 

5  D 

5  E 

5  F 

5  H 

11.5 

50. 

9. 

8.50 

LOWERS 


Mould 
No. 

I,ength 

Central 

Without  Collar 

Width 

6  anteriors 

Setup 

Width 
Full  14 
Setup 

Combined 

Bite  and  Shut 

of  Central 

Width 

Four 

Incisors 

5  C 
5  D 
5  E 
5  F 
5  H 

10.5 

38. 

8.5 

23.5 

53 


J.  Leok"  Williams,  D.D.S. 

CI.ASS  II. 
MODIFICATIONS  OF  TAPERING  TYPE 

FOUR  FORMS  IN  GRADED  SIZES 


FORM  1. — The  Severe  Modification  of  The  Tapering  Type. 


Illustration  represents  form  but  not  sizes. 


Form  1.     Class  II. 
A  severe,  nearly  typal  form. 

Sizes  from  small  to  large  from  moulds  IL,  IM,  IN,   IP,  IR. 


UPPERS 


Mould 
No. 

Length 

Central 

Without  Collar 

Width 

6  anteriors 

Setup 

width  14 
Setup 

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Bite  and  Shut 

of  Central 

Width  of 
Central 

1  L 
1  M 
1  N 
1  P 
1  R 

10.5 
11. 

53. 

55. 

120. 
122. 

9.5 
9.5 

8.5 
9. 

LOWERS 


Mould 

No. 

I<ength 

Width 

Width  14 

Combined 

Width 

Central 

6  anteriors 

Setup 

Bite  and  Shut 

Four 

Without  Collar 

Setup 

of  Central 

Incisors 

1   I. 

1  M 

1  N 

10. 

42. 

112. 

8.5 

26. 

1  P 

10. 

44. 

114. 

10. 

27. 

1  R 

54 


"A  'Nbw  Classificatiojst  of  Tooth  Toems" 


CLASS  II. 
FORM  2 — Second  Modification  of  The  Tapering  Type. 


Illustration  represents  form  but  not  sizes. 


Form  2.     Class  II. 
Slightly   modified   by   crossing   with   Class   III. 

Sizes  from  small  to  large  from  moulds  2L,   2M,   2N,  2P,   2R. 


UPPERS 


Mould 
No. 

I^ength 

Central 

Without  Collar 

Width 

6  anteriors 
set  up 

Width  14 
Setup 

Combined 

Bite  and  Shut 

of  Central 

Width  of 
Central 

L 
2  M 
2  N 
2  P 

R 

8.75 
9.75 

10.50 

41. 

44. 
47-48 

103. 
106. 

111. 

8. 
8. 
9. 

7. 

7.5 

8. 

LOWERS 


Length 

Width 

Width  14 

Combined 

Width 

Mould 

Central 

6  anteriors 

Setup 

Bite  and  Shut 

Four 

No. 

Without  Collar 

Setup 

of  Central 

Incisors 

1/ 
2  M 

8. 

33. 

99-100 

8. 

20. 

2  N 

9. 

34. 

102. 

9. 

21-22 

2  P 

10. 

37. 

108. 

9.5 

23-24 

R 

55 


J.  Leon  Williams,  D.D.S. 

CLASS  IL 
FORM  3 — The  Third  Modification  of  The  Tapering  Type. 

Illustration  represents  form  but  not  sizes. 


Form    3.      Class    II. 
Slightly  modified  by  crossing  with  Class  I. 

Sizes  from  small  to  large  from  moulds  3L,  3M,  3N,   3P,   3R. 


UPPERS 


Mould 

Length 
Central 

Width 

6  anteriors 

Width  14 

Combined 
Bite  and  Shut 

Width  of 

No. 

Without  Collar 

Setup 

Set  up 

of  Central 

Central 

Iv 

M 

3  N 

9.75 

45. 

105. 

8. 

8. 

3  P 

10.50 

50. 

124. 

8.5 

8.5 

R 

LOWERS 


Mould 
No. 

lycngth 

Central 

Without  Collar 

With 

6  anteriors 

Setup 

Width  14 
Setup 

Combined 

Bite  and  Shut 

of  Central 

width 

Four 

Incisors 

h 

M 

3  N 

92 

36. 

103. 

9. 

22. 

3  P 

92 

38. 

114. 

8. 

25. 

R 

56 


^A  ]S[ew  CLAssiFiCATio:sr  of  Tooth  Foems" 


CI. ASS  II. 

Form  4. — The  Fourth  and  Softest  Modification  of  the 
Tapering  Type. 

Illustration  represents  form  but  not  sizes. 


Form  4.     Class  II. 
Modified  by  Class  III,  a  little  more  than  Form  2. 

Sizes  from  small  to  large   from  moulds  4L,   4M,   4N,  4P,   4R. 


UPPERS 


Mould 
No. 

I^ength 

Central 

Without  Collar 

width 

6  anteriors 

Setup 

Width  14 
Setup 

Combined 

Bite  and  Shut 

of  Central 

Width  of 
Central 

4  Iv 

4  M 

8.75 

41. 

98-99 

9. 

8. 

4  N 

9.75 

44-45 

106. 

4  P 

4  R 

LOWERS 


Mould 
No. 

Length 

Central 

Without  Collar 

width 

6  anteriors 

Setup 

Width  14 
Setup 

Combined 

Bite  and  Shut 

of  Central 

Width 

Four 

Incisors 

41. 
4  M 

9. 

31.5 

95. 

9.5 

19.5 

4  N 

9. 

35. 

103. 

9.5 

22. 

4  P 

4  R 

57 


J.  Leon  Williams,  D.D.S. 

CLASS  III. 

MODIFICATIONS  OF  THE  OVOID  TYPE 
FOUR  FORMS  IN  GRADED  SIZES 


FORM  1 — The  Severe  Modification  of  The  Ovoid  Type. 


Illustration  represents  form  but  not  sizes. 


Form  1.     Class  III. 
Sizes  from  small  to  large  from  moulds  IT,   lU,   IW,   IX,   lY. 


UPPERS 


Mould 
No. 

I^ength 

Central 

Without  Collar 

Width 

6  anteriors 

Setup 

Width 
Full  14 
Setup 

Combined 

Bite  and  Shut 

of  Central 

Width  of 
Central 

1  T 
1  U 
1  W 
1  X 
1  Y 

LOWERS 


Length 

Width 

Width 

Combined 

Width 

Mould 

Central 

6  anteriors 

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Four 

No. 

Without  Collar 

Setup 

Setup 

of  Central 

Incisors 

1  T 

1  U 

1  W 

1  X 

1  Y 

58 


"A  ISTew  Classification  of  Tooth  Foems" 


CIvASS  III. 
FORM  2 — The  Second  Modification  op  The  Ovoid  Type. 


Illustration   represents  form  but  not  sizes. 


Form  2.     Class  HI. 
Sizes  from  small  to  large  from  moulds  2T,  2U,  2W,  2X,  2Y. 


UPPERS 


Mould 
No. 

Length 

Central 

Without  Collar 

Width 

6  anteriors 

Setup 

Width  14 
Setup 

Combined 

Bite  and  Shut 

of  Central 

Width  of 
Central 

2  T 
2  U 
2  W 
2  X 
2  Y 

LOWERS 


Mould 
No. 

Length 

Central 

Without  Collar 

Width 

6  anteriors 

Setup 

Width  14 
Setup 

Combined 

Bite  and  Shut 

of  Central 

Width 

Four 

Incisors 

2  T 
2  U 
2  W 
2  X 
2  Y 

59 


J.  Leon  Williams,  D.D.S. 


CLASS  III. 
FORM  3 — The  Third  Modification  of  The  Ovoid  Type. 


Illustration  represents  form  but  not  sizes. 


Form  3.     Class  III. 
Sizes  from  small  to  large   from  moulds   3T,   3U,   3W,   3X,   3Y. 


UPPERS 


Mould 
No. 

Length 

Central 

Without  Collar 

Width 

6  anteriors 

Setup 

Width  14 
Setup 

Combined 

Bite  and  Shut 

of  Central 

Width  of 
Central 

3  T 
3  U 
3  W 
3  X 
3  Y 

LOWERS 


Mould 
No. 

I^ength 

Central 

Without  Collar 

Width 

6  anteriors 

Setup 

Width  14 
Set  up 

Combined 

Bite  and  Shut 

of  Central 

Width 

Four 

Incisors 

3  T 
3  U 
3  W 
3  X 
3  Y 

60 


"A  ISTew  Classification  of  Tooth  Foems" 


CI.ASS  III. 
FORM  4 — The  Softest  Modification  of  The  Ovoid  Type. 


Illustration  represents  form  but  not  sizes. 


Form  4.     Class  III. 
Sizes  from  small  to  large  from  moulds  4T,  4U,  4W,  4X,  4Y. 


UPPERS 


Mould 
No. 

Length 

Central 

Without  Collar 

Width 

6  anteriors 

Setup 

Width  14 
Setup 

Combined 

Bite  and  Shut 

of  Central 

Width  of 
Central 

4  T 
4  U 
4  W 
4  X 
4  Y 

LOWERS 


Mould 
No. 

Length 

Central 

Without  Collar 

Width 

6  anteriors 

Setup 

Width  14 
Setup 

Combined 

Bite  and  Shut 

of  Central 

Width 

Four 

Incisors 

4  T 
4  U 
4  W 
4  X 
4  Y 

61 


J.  Leon  Williams,  D.D.S. 

ing  into  the  tapering  form,  you  select  a  tooth  with  slightly  converging 
proximal  lines  and  your  harmony  is  perfect.  Each  set  of  teeth  in  a 
series  is  numbered  and  the  length  and  width  of  the  centrals  and  com- 
bined width  of  the  six  upper  fronts  is  given  on  one  line  opposite  the 
number.  You  therefore  have  under  your  eye  every  condition  for  giv- 
ing you  exactly  what  you  want.  All  the  old  wearisome,  vexing  search 
among  the  miscellaneous  collections  of  the  trays  is  ended.  You  work 
quickly,  positively,   accurately,   artistically,   as  scientific  men  should. 

-^  *%  *% 

All  of  the  teeth  in  Class  III  are  in  an  entirely  new  field,  as  models 
of  this  beautiful  type  have  never  been  made  by  any  manufacturer  be- 
fore. And  so  far  as  my  knowledge  goes,  only  one  model  in  Class  II 
has  ever  before  been  produced.  By  classifying  and  systematizing  the 
work  I  have  therefore  given  you  a  far  wider  range  of  tooth-form  than 
you  have  ever  had  before,  and  with  comparatively  few  forms. 

And  thus,  you  see,  for  the  old  vague,  complex  and  bewildering 
effort  at  instruction  in  the  adaptation  of  teeth  to  certain  hypothetical 
temperamental  conditions,  which  nobody  ever  understood  because  they 
never  existed,  we  substitute  a  few  simple,  clear,  positive  rules,  based 
on  a  fundamental  esthetic  principle.  And  the  essence  of  that  principle 
is  the  direct  adaptation  of  tooth  form  to  facial  contour.  A  square  tooth 
for  a  square  face ;  an  oval  tooth  for  an  oval  face ;  an  ovoid  tooth  for  an 
ovoid  face,  and  teeth  with  proximal  lines  converging  toward  the  neck 
for  the  tapering  faces  with  lines  converging  toward  the  chin. 

While  the  improvements  in  the  outline  forms  and  proportions  of 
which  I  have  been  speaking  are  fundamental  improvements  in  the  new 
forms  of  teeth,  because  they  strike  at  the  very  foundation  of  good 
prosthesis,  it  has  been  possible  to  incorporate  into  the  anteriors  of  the 
new  teeth  other  improvements,  some  of  which  have  long  been  asked 
for  by  the  dental  profession.  I  shall  refer  to  these  under  the  head- 
ings of: — 

IMPEOVED  LABIAL  SUEFACES  AKD  IMPEOVED  COLOEINGS. 

Many  a  dentist  who  has  had  difficulty  in  making  a  satisfactory 
restoration  of  a  lost  natural  tooth,  even  when  the  artificial  tooth  has 

62 


"A  I^Tew  Classificatiost  of  Tooth  Fokms" 

seemed  of  the  riglit  size,  form  and  color,  has  been  at  a  loss  to  account 
for  the  difficulty,  and  has  attributed  it  to  the  difference  in  appearance 
between  the  natural  tooth  and  the  porcelain. 

The  fact  has  been  that  the  porcelain  tooth  reflected  the  light  in 
a  different  way  than  the  natural  tooth  did,  because  the  natural  tooth 
presented  a  slightly  roughened  labial  surface  which  diffused  the  light, 
while  the  porcelain  tooth  presented  a  smooth  surface  which  did  not 
diffuse  it.  (It  should  be  noted  here  that  some  natural  teeth  have  smooth 
labial  surfaces,  but  they  seem  to  be  in  the  minority,  and  are  not  as 
pleasing  in  color  as  those  with  rougher  surfaces.) 

-^  -^  *% 

I£  the  labial  surface  of  an  upper  central  which  is  beautiful  in  color 
and  softness  be  carefully  examined,  it  will  be  seen  to  present  very  deli- 
cate longitudinal  striations  due  to  the  succession  of  calcification  of  the 
ameloblasts  or  enamel  cells.  These  striations  have  a  very  constant  pat- 
tern which  is  horizontally  across  the  labial  surface  of  the  tooth,  by  a 
series  of  compound  curves.  The  striations  undergo  regular  changes  in 
form  and  size  in  different  parts  of  the  tooth. 

These  striations  work  very  important  color  effects  in  the  appear- 
ance of  the  teeth.  They  soften  the  high  lights  which  would  other- 
wise be  reflected  with  much  brilliancy  from  certain  parts  of  the  tooth, 
and  which  would  often  make  the  teeth  a  point  of  too  strong  light  to 
harmonize  well  with  the  rest  of  the  face.  They  soften  the  shadows, 
which  would  otherwise  be  too  deep.  They  do  this  by  breaking  up  the 
waves  of  reflected  light  so  that  they  are  not  returned  to  the  eye  in 
that  rhythmical  succession  given  by  polished  surfaces.  The  result  is 
that  the  whole  surface  of  the  tooth  is  rendered  considerably  softer 
than  it  would  otherwise  be. 

JSTot  only  is  this  surface  of  the  tooth  rendered  softer,  but  careful 
experiments  with  optical  instruments  seem  to  show  that  the  whole 
outline  of  the  tooth  is  given  a  softer  appearance  by  this  diffusion  of 
light. 

63 


J.  Leon  Williams,  D.D.S. 

The  methods  iu  use  for  the  commercial  production  of  porcelain 
teeth  have  not  permitted  the  reproduction  of  labial  surfaces  which  could 
diffuse  the  reflected  light  in  the  manner  just  referred  to.  We  have  had 
strong  developmental  grooves  and  occasional  cross  grooves,  possibly 
intended  to  represent  deficient  calcification.  Otherwise  the  labial  sur- 
faces have  been  smooth. 

The  result  of  the  smoothness  of  porcelain  labial  surfaces  has  been 
that  the  light  from  them  has  not  been  diffused  and  softened.  The  high 
lights  have  been  strong  and  the  shadows  deep.  The  outlines  have  been 
always  clearly  defined.  And  when  placed  beside  natural  teeth  of  even 
like  form  and  color,  they  have  presented,  to  the  observing  eyes,  differ- 
ences which  have  often  made  them  unsatisfactory.  The  general  com- 
ment was  that  the  teeth  looked  "too  glassy." 

'^  '^  '^ 

This  matter  of  diffusing  the  reflected  lights  and  giving  Trubyte 
teeth  more  natural  appearances  has  received  the  most  exacting  atten- 
tion, with  the  result  that  the  labial  surfaces  of  Trubyte  teeth  present 
enamel  markings  which  are  anatomically  correct  in  form  and  which 
soften  the  reflected  high  lights  and  shadows  in  the  same  way  the  natu- 
ral teeth  do. 

This  softening  of  the  lights  and  shadows  changes  the  whole  appear- 
ance of  the  teeth,  so  that  they  seem  to  be  of  a  different  porcelain  or 
texture  from  similar  teeth  not  so  softened. 

This  improvement,  which  I  have  passed  over  in  few  words,  is  of 
the  very  greatest  value  to  the  prosthetic  worker  who  wishes  to  render 
his  patient  a  high  type  of  service  and  receive  a  proper  fee  therefor. 
When  these  moulds  are  produced  in  facings  and  crowns,  the  full  force 
of  the  improvement  will  be  apparent  to  all. 

The  incorporation  of  these  enamel  markings,  in  correct  form,  has 
been  a  task  of  great  difficulty.  It  has  been  necessary  to  perfect  a  new 
and  improved  method  of  mould  making,  and  this  has  demanded  almost 
two  years  of  constant  labor. 

COLOE    liJf    AETIFICIAL    TEETH. 

If  the  knowledge  of  form  in  natural  and  artificial  teeth  has  been 
in  a  chaotic  condition  there  has  hardly  been  sufficient  scientific  knowl- 

64 


"A  E"e-w  Classification  of  Tooth  Foems" 

edge  of  color  in  teeth  to  justify  the  use  of  the  word  "chaotic"  or  any 
other  adjective  concerning  it.  We  have  known  practically  nothing  and 
certainly  nothing  practical  about  the  right  use  of  color  in  porcelain 
teeth. 

As  time  went  on  and  I  became  more  and  more  absorbed  in  the 
study  and  investigation  of  tooth  form  and  in  the  practical  working  out 
of  the  results  of  my  investigation  in  carving  models  for  the  Trubyte 
System,  it  became  apparent  that  some  one  else  would  have  to  take  up 
this  matter  of  analyzing  the  color  of  different  types  of  natural  teeth 
and  adapting  the  results  obtained  in  this  branch  of  our  work  to  the 
new  system  of  artificial  teeth. 

Dr.  Clapp  kindly  offered  to  take  this  work  off  my  hands,  and  he 
entered  upon  this  very  difficult  task  with  the  earnestness  and  deter- 
mination that  he  puts  into  everything  that  he  undertakes. 

This  work,  under  his  direction,  has  now  been  in  progress  for 
nearly  two  years,  and  the  first  results  are  being  embodied  in  the 
Trubyte  system  of  teeth. 

«^  -^  *<fe 

Many  progressive  dentists  here  in  America  and  others  in  Europe 
had,  for  years,  been  calling  attention  to  the  unnatural  coloration  of 
artificial  teeth,  but  no  one  had  ever  suggested  any  standard  of  color 
and  no  one  had  ever  determined  what  the  actual  colors  are  in  human 
teeth.  This,  then,  was  the  arduous  task  Dr.  Clapp  took  upon  himself. 
He  had  first  to  determine  the  actual  primary  and  secondary  colors  in 
natural  teeth,  and  he  had  then  to  discover  or  invent  a  method  of  stand- 
ardizing the  results  of  this  investigation  so  as  to  secure  a  practical 
application  of  the  knowledge  gained  to  the  coloration  of  artificial  teeth. 

He  was  fortunate  at  the  outset  in  being  able  to  secure  the  services 
of  one  of  the  world's  greatest  commercial  color  experts.  With  his  aid, 
the  colors  in  a  large  number  of  sets  of  natural  teeth  were  carefully 
analyzed  and  recorded  in  exact  terms.  The  secondary  and  tertiary  col- 
ors were  worked  out,  and  the  whole  thing  reduced  to  charts,  and  finally 
to  paintings  representing  the  exact  depth  of  color  in  different  teeth  and 
the  distribution  of  that  color. 

65 


J.  Leon  Williams,  D.D.S. 


COLOR  ANALYSIS 


u 


u 


Miss  D.  A. 


UPPERS 


,  R.  Central , 

' '  Lateral 

' '  Cuspid 

"  1st  bicuspid 

"  2nd       " 

' '  1st  molar 

L.  Central 

* '  Lateral 

' '  Cuspid 

'  *  1st  bicuspid 

"  2nd       " 

"  1st  molar. . . 


LOWERS 
L.  R.  Central 

' '      Lateral 

' '      Cuspid 

"      1st  bicuspid.. 
L.  L.  Central 

"      Lateral 

"      Cuspid 

"      1st  bicuspid.. 


Age  19 

Ht.  5.6" 

Wt.  119  lbs. 


Eyes 
Hair 
Skin 


f  Cervical 
I  Incisal 
f  Cervical 
\  Incisal 
j  Cervical 
\  Incisal 
/  Cervical 
1  Incisal 
J  Cervical 
\  Incisal 
/  Cervical 
\  Incisal 
(  Cervical 
(  Incisal 
I  Cervical 
t  Incisal 
f  Cervical 
\  Incisal 
f  Cervical  \ 
\  Incisal     J 
{  Cervical  \ 
/  Incisal     J 
{  Cervical  I 
(  Incisal     \ 


/  Cervical 
\  Incisal 
f  Cervical 
\  Incisal 
f  Cervical 
\  Incisal 
{  Cer\acal  1 
}  Incisal     j 
i  Cervical 
I  Incisal 
/  Cervical 
\  Incisal 
f  Cervical 
\  Incisal 
f  Cervncal  \ 
\  Incisal     J 


Red 


17.5 
Dead 
4.1 


43.0 
Blac 
3.0 


1.1 

1.1 

1.85 

1.85 

1.85 

1.9 

2.0 

2.0 

2.0 
2.4 


1.1 

1.1 

1.85 

1.85 

1.95 

2.0 

2.0 
2.0 
2.4 


1.0 
1.0 

2.4 
2.3 
2.6 
2.3 

2.0 


Yellow 


16.0 
k 
.88 


1.4 

1.35 

2.9 

2.7 

3.3 

3.1 

2.7 

2.6 

2.3 

3.7 

1.5 
1.4 
2.9 

2.5 
3.2 
3.1 

2.7 
2.3 
3.6 


2.5 
2.4 
3.4 
2.9 
3.3 
2.7 

2.5 


1.0 

2.5 

1.25 

2  4 

2.4 

3.4 

2.3 

2.9 

2.4 

3.1 

2.2 

2.6 

2.0 


2.5 


.20 
.34 

1.3 

1.7 

1.75 

1.85 

1.6 

1.7 

1.6 

2.3 

.20 
.38 
1.3 
1.6 
1.75 
1.8 

1.6 
1.6 

2.3 


.74 
.76 

1.6 

1.8 

1.5 

1.55 

1.5 


.74 
.95 

1.6 

1.8 

1.45 

1.5 

1.5 


Color  Developed 


Black    Orange 


6.0 

1.5 

.88 

2.12 

.20 

.90 

.34 

.76 

1.3 

.55 

1.7 

.15 

1.75 

.10 

1.85 

.05 

1.6 

.40 

1.7 

.30 

1.6 

.40 

2.3 

.10 

.20 

.90 

.38 

.72 

1.3 

.55 

1.6 

.25 

1.75 

.20 

1.8 

.20 

1.6 

.40 

1.6 

.40 

2.3 

.10 

.74 

.26 

.76 

.24 

1.6 

.80 

1.8 

.50 

1.5 

1.1 

1.55 

.75 

1.5 

.50 

.74 

.26 

.95 

.30 

1.6 

.80 

1.8 

.50 

1.45 

.95 

1.5 

.70 

1.5 

.50 

25.5  yel. 
1.1  red 


.3  yel. 

.25  " 

1.05  " 

.85  " 

1.45  •' 

1.2  " 
.7  " 
.6  " 

.3  " 

1.3  " 

.4  " 

.3  " 

1.05  " 

.65  " 

1.25  " 

1.1  " 


.3 
1.2 


1.5 

1.15 

1.0 

.6 

.7 

.4 


66 


"A  JSTew  Classification-  of  Tooth  Foems" 


Depths  of  colors  in  the  necks  of  the  upper 
anteriors. 


Depths   of   colors   in   the   incisal  halves   of 
the  upper  anteriors. 


DIAGRAMMATIC  REPRESENTATION  OF  THE  DEPTHS  OF  COLOR 
TABULATED  ON  PAGE  66. 

The  different  depths  of  color  in  different  parts  of  a  tooth  and  in  different  teeth 
can  be  diagrammatically  shown  in  charts  like  those  here  reproduced. 

The  horizontal  base  line  of  the  charts  represents  0  in  color.  Each  of  the 
parallel  horizontal  chart  lines  represents  a  depth  of  1-10  of  a  unit,  upward  from  0. 
The  line  locating  the  gray  in  the  teeth  is  drawn  solid.  That  representing  the  orange 
is  drawn  in  dashes  and  that  representing  the  yellow,  in  dots.  This  set  of  teeth  showed 
no  other  colors.  This  person's  hair  is  dead  black,  the  eyes  are  brown,  and  the 
skin  showed  a  good  deal  of  red. 

The  charts  show  that  the  necks  of  the  upper  centrals  and  laterals  in  this  set 
exhibit  less  gray  than  the  cutting  edges,  but  more  orange  and  yellow.  The  cuspids 
exhibit  practically  the  same  amount  of  gray  and  orange  throughout  the  teeth,  but 
the  necks  show  more  yellow  than  the  cutting  edges.  This  free  yellow  gives  these 
cuspids  their  character. 

The  necks  of  one  lower  central  and  both  lower  laterals  in  this  set,  exhibit  less 
gray  than  the  cutting  edges,  but  the  necks  of  the  lower  laterals  exhibit  more  orange 
and  yellow.  The  lower  cuspids  exhibit  practically  an  even  depth  of  gray  through- 
out, but  much  more  orange  and  yellow  in  the  necks.  There  is  a  good  deal  more 
orange  in  the  lower  cuspids  than  in  the  upper  cuspids. 


Depths  of  colors  in  the  necks  of  the  lower  Depths    of   colors   in   the   incisal   halves   of 

anteriors.  the  lower  anteriors. 

Illustration  No.  32 


67 


J.  Leon  Williams,  D.D.S. 

Some  of  the  difficulty  of  that  work  may  be  understood  when  I  tell 
you  that  it  has  taken  two  years  to  gain  the  necessary  information,  and 
that  in  addition  to  our  own  efforts  from  one  to  three  experts  have  been 
working  steadily.  They  state  that  they  never  saw  such  difficult  and 
delicate  work,  nor  such  exacting  taskmasters  as  we  have  proven.  How 
ever,  we  have  gotten  at  least  the  greater  part  of  what  we  want  and 
have  incorporated  it  into  Trubyte  Teeth. 

Let  me  set  before  you  some  facts  regarding  the  distribution  of 
colors  in  different  anterior  teeth.  Let  us  take  as  a  shade  in  which  to 
work,  Twentieth  Century  shade  7.  The  color  in  the  upper  central  will 
be  found  distributed  about  as  it  is  in  the  shade  tooth,  because  the 
manufacturers  seem  to  have  paid  pretty  close  attention  to  the  shading 
in  the  upper  centrals,  and  to  have  imitated  it  pretty  well.  Their  error 
consists  in  the  fact  that  they  have  applied  this  form  of  shading  to  all 
the  anterior  teeth. 

The  shading  of  the  upper  laterals  is  very  much  like  that  of  the 
upper  centrals  in  depth,  but  the  incisal  third  of  the  lateral  is  darker. 
This  does  not  seem  quite  logical  in  view  of  the  fact  that  the  incisal 
half  of  this  tooth  is  largely  composed  of  the  enamel  plates,  with  only 
a  small  amount  of  dentine.  But  I  have  the  analyses,  the  charts  and 
the  color  drawings  before  me  as  I  write,  and  they  indicate  that  the 
incisal  half  of  the  upper  lateral  has  more  color  than  the  same  portion 
of  the  upper  central.  It  is  especially  distinguished  by  the  presence 
of  more  gray. 

-^  -^  -^ 

The  cervical  half  of  the  upper  cuspid  shows  more  color  than  the 
cervical  half  of  the  upper  central  or  lateral,  while  the  cuspid  shows  the 
widest  variation  in  individual  teeth,  and  that  without  any  apparent 
relation  to  the  color  in  the  incisal  halves  of  the  central  and  lateral. 
It  has,  of  course,  always  been  known  in  a  general  way,  from  observa- 
tion, that  the  cuspids  were  darker  than  the  centrals,  but  there  has 
never  been  any  exact  knowledge  about  the  conditions  of  this  variation. 

The  depth  of  color  in  the  lower  anteriors,  as  compared  with  the 
depths  of  color  in  the  upper  anteriors,  differs  markedly  in  different  indi- 
viduals and  apparently  in  different  races.  I  think  a  fair  statement  of 
it  would  be  that  the  colors  seen  in  the  upper  teeth  are  slightly  deeper 
in  the  lower  anteriors.  The  cutting  edges  are  also  generally  deeper  in 
color.  This  makes  the  color  throughout  each  tooth  in  the  lower  an- 
teriors more  uniform.  The  effect  of  the  deeper  average  of  color  and 
of  the  uniformity  affords  a  pleasing  contrast  with  the  upper  teeth. 

68 


VARIATIONS  OF  COLOR  IN  NATURAL  TEETH 


GRAY 


ORANGE 


GREEN 


VIOLET 


Illustration  No. 


VARIATIONS  OF  COLOR  IN  NATURAL  TEETH— Continued 


YELLOW 


BLUE 


RED 


Illustration  Xo.  34 


"A  ^Ew  CLAS.siFiCATio:sr  OF  Tooth  Forms" 

These  color  effects  have  been  achieved  in  Trubyte  teeth  by  placing 
the  dentine  and  enamel  bodies  in  such  way  as  to  reproduce  the  natural 
variations.  This  has  been  made  possible  by  the  translucency  of  the 
porcelain  from  which  these  teeth  are  made. 

These  colors  can  be  properly  placed  only  by  people  especially 
trained  and  by  allowing  them  much  more  time  than  is  required  for 
shading  the  ordinary  porcelain  teeth  of  commerce.  This  necessarily 
increases  the  cost  of  the  teeth,  but  this  increase  in  cost  is  trifling  when 
the  advantages  gained  are  considered. 

The  results  attained  in  coloring  Trubyte  teeth  are  superior  to 
those  w^hich  will  ordinarily  be  accomplished  by  staining  and  burning 
teeth  by  the  individual  dentist.  The  colors  are  in  the  teeth,  are  the 
result  of  proper  placing  of  the  dentine  and  enamel  bodies,  and  are 
under  the  glaze.  The  results  are  an  enormous  stride  in  advance  of 
what  has  been  heretofore  commercially  offered. 

One  who  has  not  closely  studied  the  colors  in  natural  teeth  can 
hardly  realize  how  delicate  and  beautiful  is  the  color  scheme  by  which 
nature  adorns  a  really  fine  set  of  teeth.  The  primary  colors,  red,  blue 
and  yellow  are,  as  one  who  has  made  a  scientific  study  of  color  would 
expect,  found  in  every  human  tooth.  The  blending  of  these  primary 
colors  produces  the  secondary  colors — the  orange,  green  and  violet.  It 
is  very  interesting  to  note  the  parallelism  of  form  and  color  in  teeth 
as  elsewhere  in  nature. 

As  one  or  other  of  the  three  primary  types  of  form  is  usually 
dominant  in  every  upper  central  incisor,  and  to  a  certain  degree  in 
every  human  tooth,  so  one  or  other  of  the  three  primary  colors  is 
generally  dominant  and  a  color  expert  might  classify  most  human  teeth 
as  pink,  blue  or  yellow. 

'^  '^  '^ 

As  much  the  larger  proportion  of  teeth  are,  in  form,  the  result  of 
the  crossing  or  blending  of  the  primary  forms,  so  also  in  color  the 
blending  or  mixing  of  the  primary  colors  produce  a  great  variety  of 
secondary  or  intermediate  colors  in  which  orange,  green  and  violet 
are  clearly  seen. 

It  is  a  rare  thing  to  find  two  teeth  in  any  given  mouth  of  exactly 
the  same  color.  Just  as  it  is  rare  to  find  a  pair  of  teeth  on  different 
sides  of  the  mouth  of  the  same  shape.  It  is  these  slight  variations  in 
form  and  color  which  give  great  beauty,  harmony  and  naturalness  to 
a  fine  set  of  natural  teeth,  and  it  is  mechanical  regularity  in  form  and 
sameness  in  coloring  which  make  artificial  teeth,  as  they  have  hereto- 
fore been  made,  so  false  looking,  so  unnatural  and  repulsive. 

69 


J.  Leon  Williams,  D.D.S. 

As  a  more  detailed  account  of  the  results  of  our  investigation 
into  the  color  of  natural  teeth  will  shortly  be  published  in  book  form  * 
and  offered  to  the  profession,  I  shall  give  here  but  a  brief  resume  of 
this  work.  The  table  on  page  66  gives  a  color  analysis,  according  to 
the  scientific  method  we  have  followed,  of  a  single  set  of  natural  teeth, 
and  on  the  following  page  will  be  seen  a  diagrammatic  representation 
of  the  depths  of  color  in  the  incisors  according  to  the  table. 

The  first  three  columns  in  the  table  show  the  percentages  of  the 
standard  colors  used  to  determine  or  develop  the  actual  colors  in  the 
tooth  which  are  indicated  in  the  three  columns  on  the  right. 

When  I  tell  you  that  for  every  figure  set  down  in  those  columns 
a  considerable  number  of  trials  with  optical  apparatus  of  the  most 
exacting  nature  had  to  be  made  before  the  final  result  was  reached, 
you  will,  I  think,  begin  to  understand  why  this  work  could  not  be 
completed  quite  as  rapidly  as  some  of  our  impatient  confreres  thought, 
and  also  why  a  slight  advance  in  the  cost  of  these  teeth  has  been  neces- 
sary. Trubyte  teeth,  as  I  have  said,  are  "shaded"  on  the  basis  of  this 
investigation  into  the  color  of  natural  teeth.  The  upper  central  is 
always  of  the  shade  on  the  guide.  This  is  the  dominant  color  of  the 
set  the  shading  of  which  is  accomplished  by  varying  the  depth  of  this 
color.  The  color  in  the  upper  laterals  is  more  evenly  distributed 
throughout  the  tooth  just  as  we  find  it  in  nature. 

The  upper  cuspids  are  more  deeply  shaded  in  both  cervical  and 
incisal  halves  than  either  the  centrals  or  the  laterals.  The  color  in  the 
bicuspids  and  molars  is  slightly  deeper. 

The  color  in  the  incisal  halves  of  the  lower  anteriors  is  slightly 
deeper  than  in  the  incisal  halves  of  the  uppers. 

*%  '^  •% 

For  the  first  time  in  the  commercial  history  of  porcelain  teeth  they 
are  now  supplied  to  the  dentist  of  a  color  closely  approximating  that 
found  in  natural  teeth.  The  color,  being  based  on  nature,  gives  a  far 
finer  effect  than  the  arbitrary  method  of  hand  staining  or  the  still  more 
imperfect  method  of  selecting  a  variety  of  colors  from  different  sets  and 
assembling  them  into  one. 

Dentures  made  with  teeth  shaded  in  this  natural  way  are,  artis- 
tically, so  superior  to  those  made  of  one  shade  that  a  comparison  can- 
not well  be  made. 

In  form,  in  surface  texture  and  in  color  the  Trubyte  System  of 
teeth  has  reached  such  a  high  standard  of  achievement  that  I  hope 
and  believe  the  finest  artistic  and  mechanical  ability  in  our  profession 

*  Prosthetic  Articulation. 

TO 


Illustration  No.   35 

Five  Stages  of  Wear  of  Natural  Teeth:  A.  Unworn  Stage.  B.  Greatest  Efficiency  Stage. 
C.  Reduced  Efficiency  Stage.  D.  Much  Worn  Stage.  E.  Stage  of  Extreme  Wear.  Trubyte 
teeth  exhibit  the  stage  of  wear  shown  in  Figure  A  and  the  depth  of  bite  shown  in  Figure  B. 


Illustration  No.   36 

Figure  A  shows  occlusal  surfaces  of  upper  and  lower  molars  ground  to  articulating  form  after 
method  formulated  by  Dr.   Bonwill. 

Figure   B  shows  same  molars  occluded. 

Figure  C  shows  longitudinal  section  of  same  teeth. 

Figure  D  shows  the  same  occlusal  surfaces  of  the  anatomical  moulds  of  the  Dentists  Supply 
Company.  These  are  carved  to  much  more  nearly  correct  anatomical  form  than  were  the  teeth 
of  Dr.   Bonwill's  time. 

Figure  E  shows  molars  occluded.  The  longitudinal  groove  is  entirely  different  in  charactei 
from  that  shown  in  Figure  B.  The  upper  buccal  cusp  does  not  overhang  the  lower  molar  as  in 
Figure  B.     The  depth  of  bite  in  these  teeth  is  only  half  as  great  as  in  those  shown  in  Figure  B. 

Figure  F  shows  a  longitudinal  section  of  the  same  teeth. 

Figure  G  shows  the  occlusal  surfaces  of  Trubyte  teeth,  with  the  formation  for  cracking, 
tearing  and  cutting. 

Figure  H  shows  Trubyte  first  molars  occluded.  ■  n  j 

Figure  I  shows  a  longitudinal  section  of  these  teeth.  Instead  of  presenting  the  flat  opposed 
surfaces  shown  in  Figure  C  or  the  single  convex  surfaces  shown  in  Figure  F,  these  teeth  exhibit 
from  two  to  five  grooves  and  from  three  to  six  cusps   each. 


"A  l^Ew  Classification  of  Tooth  Foems" 

■will  be  aroused  by  their  appearance  and  stimulated  to  tbe  production 
of  such  results  as  have  never  before  been  known  in  the  history  of 
dentistry. 

TEUBYTE    BICirSPIDS    AND    MOLAES. 

And  now  I  come  to  a  part  of  the  paper  which  describes  mechanical 
advances  of  such  importance  to  the  dentist  and  to  the  patient  as  a 
masticating  animal,  that,  from  this  point  of  view  also,  it  will  hardly 
be  possible  to  exaggerate  the  advantages  of  the  new  teeth.  I  refer  to 
the  greatly  improved  forms  of  the  masticating  surfaces  of  the  bicuspids 
and  molars  perfected  by  my  associate,  Professor  Dr.  Gysi. 

Professor  Gysi  has  established  the  fact  that  proper  forms  of  porce- 
lain bicuspids  and  molars  cannot  be  produced  by  copying  natural 
teeth,  because  at  no  time  do  the  natural  teeth  present  all  the  charac- 
teristics essential  to  artificial  teeth. 

It  is  logical  that  this  should  be  so.  The  natural  teeth  are  fixed  in 
the  jaw.  In  adult  life  they  are  capable  of  a  masticating  force  of  from 
100  to  300  pounds,  with  perhaps  an  average  of  150  pounds.  In  early 
life  they  exhibit  deep  bites  and  great  efficiency.  In  later  life  they  ex- 
hibit relatively  flat  bites  and  require  the  exercise  of  great  force  to 
make  them  efficient. 

Artificial  teeth  on  dentures  are  not  firmly  fixed  in  the  mouth  and 
on  bridges  are  less  firmly  fixed  than  when  each  tooth  has  its  own 
healthy  root.  Dentures  are  believed  to  be  capable  of  exerting  a  pres- 
sure not  greatly  in  excess  of  15  pounds,  perhaps  20  or  25  pounds  as  a 
maximum,  as  compared  with  the  150  pounds  of  the  natural  teeth. 
Bridge  teeth  are  capable  of  exerting  less  power  than  individual, 
healthy  natural  teeth. 

•^  %  '^ 

Artificial  teeth,  then,  with  one-tenth  the  power  of  the  natural  teeth, 
must  discharge  the  same  functions  as  the  natural  teeth,  or  the  food 
cannot  be  properly  prepared  for  digestion.  They  must  exhibit  shallow 
bites  in  order  that  the  dentures  or  the  bridge  may  not  be  subjected  to 
severe  lateral  strains.  Teeth  which  will  function  efficiently  and  be 
stable  under  such  conditions  cannot  be  formed  by  copying  natural 
teeth,  which  were  designed  to  function  under  very  different  conditions. 
They  can  be  made  only  by  applying  engineering  principles  to  the 
designing  of  surfaces  which  shall  function  under  actual  conditions, 
just  as  the  engineer  designs  his  bridge  for  the  load  it  must  carry. 

In  the  brief  space  of  time  left  me,  I  shall  draw  your  attention  to 
the  application  of  these  engineering  principles  only  for  the  accomplish- 
ment of  some  of  the  greater  objects  sought  in  Trubyte  bicuspids  and 
molars.     The  points  are: 

71 


J.  Leon  Williams,  D.D.S. 

Proper  opening  and  closing  articulation  in  bicuspids. 

Proper  sliding  articulation  in  the  molars. 

High  cusps,  deep  fosssc  and  sulci  with  shallow  bites. 

A  large  number  of  properly  interacting  facets  on  the  occlusal 
surfaces  of  the  molars. 

Precisely  as  1  have  followed  the  general  natural  form  in  design- 
ing the  Trubyte  System  so  Dr.  Gysi  has  based  the  forms  of  his  masti- 
cating surfaces  on  nature,  but  he  has  greatly  improved  on  l^ature  in 
eflficiency  of  mastication  as  I  have  improved  on  form. 

«<fe  -%  *<& 

PEOPEE  OPENING  AND  CLOSING  ARTICULATION  IN  BICUSPIDS. 

Artificial  bicuspids  have  heretofore  been  merely  little  molars. 
They  have  exhibited  the  same  form  of  sliding  articulation  as  the 
molars.  This  is  anatomically  incorrect  and  deprives  the  patient  of 
the  benefits  to  be  derived  from  the  very  important  functions  of  the 
bicuspids.  Their  functions  are  to  catch,  hold,  and  crack  brittle  foods, 
and  to  pierce  between  fibers  which  have  been  placed  along  them  and 
are  being  held  by  the  sliding  articulation  of  cuspids  and  molars. 

Bicuspids  can  discharge  these  important  functions  only  by  exhib- 
iting an  opening  and  closing  articulation  while  the  cuspids  and  molars 
are  in  sliding  articulation.  Trubyte  bicuspids  exhibit  this  most  impor- 
tant form  of  Articulation. 

PEOPEE    SLIDING   ARTICULATION    IN    THE    MOLAES. 

The  articulation  desired  in  the  molars  is  entirely  different  from 
that  in  the  bicuspids.  When  the  teeth  in  the  lower  jaw  come  up 
against  those  in  the  upper,  with  food  between  them,  the  buccal  and 
lingual  cusps  should  interdigitate  to  prevent  the  escape  of  solid  food, 
and  as  the  jaw  returns  to  the  position  of  central  occlusion,  the  opposing 
upper  and  lower  cusps  should  maintain  a  certain  form  of  sliding 
articulation.  This  form  of  articulation  is  very  different  in  character 
from  that  heretofore  possible  to  porcelain  molars. 

Porcelain  molars  which  have  heretofore  been  offered  have  articu- 
lated by  the  sliding  of  one  cusp  past  another.  This  is  effective  to  a 
certain  degree,  but  not  sufficiently  so  to  render  porcelain  teeth  efficient 
under  the  small  pressure  which  they  can  exert.  It  is  necessary  to  the 
maximum  of  efficiency  that  each  of  these  cusps  should  cut  across  the 
opposing  cusp  in  much  the  same  way  a  barber  draws  a  razor  across  a 
strap,  or  like  the  action  of  the  figures  shown  in  Illustration  l^o.  38. 

This  action  greatly  increases  the  cutting  efficiency  of  the  teeth  by 
causing  each  ridge  to  cut  throughout  its  length,  instead  of  for  a  short 
distance  only. 

72 


T" 


o 


The    bone    cracking   teeth    of    the    dog. 


Similar    cracking    action    by    human    bicuspids. 


>  r »   ^ 


Buccal    cusps    interdigitate    in    articulation. 


Diagrammatic  representation  of  a  grain  trap. 
Same   trap  in  Trubyte   bicuspids. 


Lingual     cusps    open    to    receive    seeds    and 
grains. 


Diagram  of  tearing  action. 
Illustration  No.   27 


"A  jSTew  Classificatioit  of  Tooth  Foems" 

The  formation  of  cusps  for  such  interaction  is  possible  only  by 
the  application  of  engineering  principles.  I  have  seen  the  formulae 
and  the  methods  by  which  Professor  Gysi  has  arrived  at  these  results, 
and  they  are  as  complicated  as  the  desigTiing  of  a  cantilever  bridge. 
The  action  of  each  part  of  each  tooth  has  been  known  before  an  instru- 
ment was  taken  in  hand  for  the  carving.  It  is  the  highest  form  of 
praise  to  say  that  the  resulting  teeth  are  as  near  to  the  theoretical 
results  as  anything  in  porcelain  can  be.  They  set  up  easily  and  func- 
tion efficiently. 

It  must  not  be  thought  that  because  I  have  quoted  Professor  Grysi 
as  to  the  application  of  engineering  principles  to  the  formation  of 
these  surfaces,  nature's  laws  have  been  departed  from,  and  unnatural 
forms  produced.  Such  is  not  the  case.  Nature  is  the  most  consum- 
mate engineer  of  us  all.  She  adapts  her  forms  to  function  with  the 
exercise  of  the  smallest  possible  force,  and  with  the  least  disturbance 
of  parts. 

•^  -^  '^ 

The  laws  which  she  employed  for  the  formation  of  the  permanent 
teeth  and  which  made  them  efficient  with  the  relatively  small  masticat- 
ing force  of  the  child  have  been  employed.  The  depth  of  bite  has 
been  reduced  so  that  it  is  much  more  shallow  than  in  efficient  human 
teeth,  and  only  half  as  deep  as  in  the  present  anatomical  moulds. 

The  ridges  have  been  arranged  to  present  the  longest  cutting 
action  possible  and  to  bring  into  action  a  large  number  of  small  sur- 
faces, interacting  properly,  in  order  that  the  food  may  be  more  thor- 
oughly masticated.  The  forms  of  these  ridges  have  been  carefully 
designed  by  applying  the  laws  exhibited  in  human  teeth  at  the  period 
of  their  greatest  masticating  efficiency. 

I  have  been  asked  whether  teeth  so  accurately  formed  can  be  set 
up  by  the  average  dentist.  In  reply  let  me  say  that  they  can  be  better 
set  than  any  other  and  less  accurate  forms.  They  cannot  always  or 
perhaps  often  be  articulated  for  individual  peculiarities  of  jaw  move- 
ment without  some  small  amount  of  grinding,  but  this  grinding  can 
be  done  with  the  carborundum  and  glycerine,  and  will  be  neither 
tedious  nor  difficult.  Little  or  no  grinding  with  a  stone  should  be 
necessary. 

IMPROVED    FORMATIONS    IN    CUSPID    EDGES. 

Both  Dr.  Gysi  and  myself  have  contended  from  the  first  that  the 
highest  success  in  the  making  of  artificial  teeth  cannot  be  reached  by 
baldly  copying  natural  teeth. 

73 


J.  Leon  Williams,  D.D.S. 

Dr.  Gysi  makes  the  same  claim  from  the  point  of  view  of  efficiency 
in  mastication.  He  has  originated  a  phrase  that  will  become  classic  in 
prosthetic  dentistry  which  is  that  "the  problem  of  restoring  mastica- 
tion is  an  engineering  problem." 

The  cutting  edges  of  the  cuspids  present  the  most  anterior  example 
of  the  application  of  engineering  principles.  For  these  edges  must  be 
quite  differently  formed  in  porcelain  teeth  than  they  are  in  newly 
erupted  natural  teeth. 

IsTatural  upper  cuspids  are  often  very  beautiful  in  form,  and  before 
wear  has  mutilated  them,  present  long  and  often  pleasing  cusps.  These 
are  the  forms  which  have  generally  been  reproduced  in  porcelain  teeth. 
They  are  the  forms  which  have  made  it  practically  impossible  to 
arrange  the  upper  and  lower  cuspids  properly,  without  extensive  grind- 
ing of  the  edges.    Many  find  this  grinding  difficult  of  accomplishment. 

The  edges  of  the  upper  and  lower  cuspids  here  shown  have  been 
shaped  to  function  properly.  The  anterior  facet  on  the  edge  of  the 
lower  cuspid  is  always  short,  so  that  it  may  occlude  with  the  distal 
facet  on  the  cutting  edge  of  the  upper  lateral.  The  mesial  facet  of  the 
upper  cuspid  is  usually  long,  in  normal  dentures  after  wear,  in  order 
that  this  tooth  may  both  occlude  and  articulate  with  the  lower  cuspid, 
and  that  the  point  of  the  upper  cuspid  may  pass  through  the  inter- 
dental space  posterior  to  the  lower  cuspid  and  not  climb  on  the  lower. 
This  is  one  of  the  most  important  relations  in  the  articulation  of  den- 
tures, and  has  heretofore  been  one  of  the  most  difficult  to  attain.  The 
fact  that  it  may  easily  be  attained  with  Trubyte  teeth  will  greatly 
facilitate  the  arrangement  of  these  teeth  and  their  efficiency  in  mastica- 
tion. 

'^  '^  '^ 

SUMMARY. 

A  brief  summary  of  the  facts  and  principles  involved  in  this 
system  of  artificial  teeth: 

1st.  This  system  is  based  on  the  new  classification  of  the  natural 
teeth  which  I  have  discovered,  the  essential  feature  of  which  is  the 
three  primary  or  primitive  forms  of  the  upper  central  incisors  common 
to  all  races  of  men  and  the  anthropoid  apes. 

2d.  By  the  crossing  or  combining  of  these  primary  forms  every 
conceivable  form  of  human  tooth  can  be  produced. 

3d.  By  applying  a  knowledge  of  design  to  the  three  primary 
forms  of  natural  teeth  a  system  of  teeth  has  been  produced  in  which 
all  the  lines  and  contours  of  any  given  set  are  in  more  perfect  har- 
mony and  balance  than  we  usually  find  in  Nature. 

74 


Food  cells  are  isolated  and  the  cell  walls 
broken  by  the  rubbing  together  of  the  facets. 
The  rubbing  action  is  diagrammatically  shown 
by  the  mortar  and  pestle  in  which  substances 
are    pulverized. 


Diagrammatic  illustration  of  the  cutting  ac- 
tion exhibited  by  opposed  ridges  and  facets  in 
Trubyte  molars.  If  the  point  A  of  the  upper 
block  be  carried  to  the  point  C  of  the  lower 
block,  and  then  the  upper  block  be  so  moved 
as  to  bring  the  point  B  directly  over  the 
point  D  ot  the  lower  block,  each  of  the 
opposed  ridges  will  cut  throughout  its  length 
with  a  drawing  motion.  This  is  the  longest 
and  most  efficient  "cut"  possible  to  these 
ridges. 


_ks^-^^ 


Diagrammatic  representation  of  the  plan  on 
which  artificial  molars  have  generally  been 
shaped  in  the  past.  The  broad  surfaces  can- 
not cut  up  foods  to  isolate  the  cells.  They 
can  be  approximated  only  by  the  exercise  of 
great  force. 


A.  A  cross  section  of  Trubyte  lower  first 
and  second  molars  showing  five  ridges  in 
each  tooth.  B.  Ridges  and  facets  in  Trubyte 
upper  and  lower  molars  opposed.  C.  The 
cross  sections  shown  above  were  made  at  the 
dotted  line   in   this   figure. 


Illustration  No.   38 


"A  JSTeW  CliASSIFICATION  OF  ToOTH  FoEMs" 

4th.  As  the  three  primary  forms  of  human  teeth  are  coromon  in 
all  races,  therefore  a  system  of  artificial  teeth  founded  on  these 
primary  forms  is  equally  suitable  for  all  races  of  men  civilized  or 
savage. 

5th.  As  investigation  shows  that  there  are  but  a  few  characteristic 
forms  of  human  faces  which  can  all  be  grouped  in  a  series  of  a  dozen 
or  less,  to  which  groups  all  slight  variations  in  form  may  be  referred, 
therefore  a  few  forms  or  types  of  teeth,  very  carefully  designed  and 
modeled  to  harmonize  with  the  more  characteristic  forms  of  faces, 
are  immeasurably  better  suited  to  the  production  of  natural  and  artistic 
effects  in  dental  prosthesis  than  any  number  of  moulds  produced 
indiscriminately  and  without  any  knowledge  of  the  above-mentioned 
fundamental  facts. 

6th.  A  close  study  of  the  relationship  of  the  contour  lines  of  the 
teath  and  face  has  enabled  me  to  design  artificial  teeth  that  will  be 
found  to  give  more  perfect  harmony  with  many  faces  than  did  the 
natural  teeth  of  that  subject,  the  reason  for  this  being  that  the  laws  of 
heredity  as  exhibited  in  mixed  races  rarely  permits  a  perfect  harmony 
in  the  different  features  of  the  body. 

7th.  The  arrangement  of  this  system  of  teeth  into  classes  and 
groups  based  on  jSTature  and  corresponding  with  the  forms  of  faces  for 
which  they  are  designed,  both  being  shown  in  illustrations  placed  side 
by  side,  enables  the  dentist,  aided  by  the  very  clear  and  simple  table  of 
classification,  to  select  the  teeth  best  suited  for  any  case  with  an  ease, 
economy  of  time,  and  certainty  of  results  never  before  approached. 

8th.  A  method  of  finishing  the  labial  surfaces  of  the  plaster  models 
for  artificial  teeth,  and  the  accurate  transfer  of  this  to  the  moulds  in 
which  the  teeth  are  cast,  has  been  devised  with  the  result  that  a  perfect 
imitation  of  the  surface  texture  of  a  fine  natural  tooth  has  been  secured. 
The  esthetic  value  of  this  one  feature  of  the  new  system  of  teeth  is  suffi- 
cient to  merit  the  indorsement  of  all  progressive  dentists. 

9th.  A  method  of  coloring  porcelain  teeth  has  been  worked  out  by 
strictly  scientific  methods,  based  on  a  color  analysis  of  the  finest  natural 
teeth,  and  applied  to  the  Trubyte  System  of  teeth,  producing  beautiful 
natural  effects  far  beyond  anything  previously  accomplished. 

10th.  My  associate  in  the  work  of  producing  the  Trubyte  System 
of  teeth.  Professor  Dr.  AHred  Gysi,  has  given  years  to  the  study  of  the 
mechanical  principles  involved  in  mastication  and  to  all  the  conditions 
necessary  in  artificial  teeth  for  the  highest  possible  efficiency  in  the 
performance  of  this  function.  Basing  his  work  entirely  upon  nature,  as 
I  have  in  designing  the  forms  of  teeth,  he  has  recognized  that  the  con- 
ditions under  which  mastication  must  be  performed  with  artificial 
teeth  are  totally  different  from  those  which  obtain  in  the  use  of  natural 

75 


J.  Leon  Williams,  D.D.S. 

teeth.  He  has  therefore  adapted  the  natural  cusp,  groove  and  sulci  for- 
mation in  the  relations  of  the  upper  and  lower  teeth  in  such  a  way  as 
to  secure  far  greater  efficiency  in  mastication  thanwould  be  possible  even 
with  the  finest  natural  teeth  if  inserted  on  plates  as  artificial  dentures. 
While  the  cusps  are  high  and  the  fossiP  and  sulci  deep  in  the  new  teeth, 
thus  making  them  very  effective  in  holding,  tearing  and  grinding  food, 
yet  the  ''bite"  is  actually  more  shallow  than  in  efficient  natural  teeth 
or  in  other  porcelain  teeth  which  manifest  even  slight  efSciency.  This 
permits  easy  and  comfortable  gliding  of  the  upper  and  lower  teeth  on 
each  other  in  lateral  and  in  backward  and  forward  movements. 

With  all  of  these  advantages  of  scientific  form  and  accuracy  in  all 
their  features  the  new  teeth  will  be  found,  when  the  dentist  is  once  accus- 
tomed to  them,  more  easy  to  arrange  on  any  form  of  articulator  than  any 
teeth  heretofore  made,  the  perfection  of  the  relations  of  the  upper  and 
lower  teeth  showing  at  once  exactly  where  they  should  be  placed. 

Gentlemen,  speaking  not  only  for  myself,  but  for  all  who  have 
taken  part  in  this  work,  I  am  expressing  my  most  sincere  convictions, 
when  I  say  that  no  more  concentrated  and  determined  effort  has  ever 
been  made  in  the  interests  of  dentistry  than  that  involved  in  this  new 
system  of  artificial  teeth. 

Scarcely  more  than  the  bare  results  and  conclusions  could  be  em- 
bodied in  this  presentation  of  the  subject.  A  detailed  account  of 
all  the  experiments  made,  of  all  the  scientific  work  done  during  the 
past  four  or  five  years,  would  fill  a  large  volume. 

It  has  been  our  firm  determination  to  do  this  work  so  well  that  it 
should  be  done  for  all  time.  It  has  been  our  desire  and  intention  to  set 
the  standard  of  prosthetic  dentistry  so  far  above  the  position  it  has  hith- 
erto occupied  as  to  make  it  impossible  from  this  day  henceforward  for 
any  self-respecting  dentist  to  continue  working  in  the  old  ways  and 
with  the  old  materials. 


76 


]\10LAK  BLOCKS. 


OCCLUSAL 


^IH^^iiw^**V 


CERVICAL^ 


LINGUAL 


Dr.  Gjsi  has  invented 
a  new  form  of  bicuspids 
and  malars  which  I  feel 
sure  will  be  found  most 
convenient  in  practical 
work.  He  calls  this  form 
Molar  Blocks,  because  the 
bicuspids  and  molars  of 
each  side  are  joined  into  a 
solid  block. 

The  Molar  Blocks  dif- 
fer in  very  important  ways 
from  the  gum  blocks  to 
which  many  of  us  have 
been  accustomed.  Those 
gum  blocks  were  designed 
for  occlusion  but  not  for 
articulation,  and  it  is 
pretty  nearly  inipossil;)le  to 
articulate  them.  These 
Molar  Blocks  are  designed 
to  facilitate  articulation, 
and  to  that  end  Dr.  Gysi 
has  worked  out  the  com- 
pensating and  lateral 
curves  in  the  occlusal  sur- 
faces, so  that  when  set  in 

the  occluding  position  the  work  of  articulating  the  teeth  is  already  well 

advanced. 

Dr.  Gysi  states  that  it  is  most  advantageous  to  offer  these  blocks 

in  the  curves  common  to  the  average  inclinations  of  the  condyle  paths, 

because  a  slight  inclination  of  the  entire  blocks  adapts  them  to  any 

greater  steepness  of  curves. 

These  blocks  may  be  articulated  in  much  less  time  than  single  teeth. 

It  is  much  easier  to  perfect  the  articulation  in  its  finer  details,  because 

single  teeth  cannot  move  out  of  position,  and  because  the  proper  relations 

of  the  several  teeth  are  already  determined. 

The  occlusal  surfaces  of  these  blocks  exhibit  the  same  characteristics 

as  the  single  teeth  and  are  efficient  in  the  same  unusual  degree. 


iY1l3>   <ti3B 


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